Vitamin D Tied to Women's Cognitive Performance
Two new studies appearing in the Journals of Gerontology Series A: Biological Sciences and Medical Sciences show that vitamin D may be a vital component for the cognitive health of women as they age.
Higher vitamin D dietary intake is associated with a lower risk of developing Alzheimer's disease, according to research conducted by a team led by Cedric Annweiler, MD, PhD, at the Angers University Hospital in France.
Similarly, investigators led by Yelena Slinin, MD, MS, at the VA Medical Center in Minneapolis found that low vitamin D levels among older women are associated with higher odds of global cognitive impairment and a higher risk of global cognitive decline.
Slinin's group based its analysis on 6,257 community-dwelling older women who had vitamin D levels measured during the Study of Osteopathic Fractures and whose cognitive function was tested by the Mini-Mental State Examination and/or Trail Making Test Part B.
Very low levels of vitamin D (less than 10 nanograms per milliliter of blood serum) among older women were associated with higher odds of global cognitive impairment at baseline, and low vitamin D levels (less than 20 nanograms per milliliter) among cognitively-impaired women were associated with a higher risk of incident global cognitive decline, as measured by performance on the Mini-Mental State Examination.
Annweieler's team's findings were based on data from 498 community-dwelling women who participated in the Toulouse cohort of the Epidemiology of Osteoporosis study.
Among this population, women who developed Alzheimer's disease had lower baseline vitamin D intakes (an average of 50.3 micrograms per week) than those who developed other dementias (an average of 63.6 micrograms per week) or no dementia at all (an average of 59.0 micrograms per week).
These reports follow an article published in the Journals of Gerontology Series A earlier this year that found that both men and women who don't get enough vitamin D -- either from diet, supplements, or sun exposure -- may be at increased risk of developing mobility limitations and disability.
Vitamin D = lower rates of tooth decay
A new review of existing studies points toward a potential role for vitamin D in helping to prevent dental caries, or tooth decay.
The review, published in the December, 2012 issue of Nutrition Reviews, encompassed 24 controlled clinical trials, spanning the 1920s to the 1980s, on approximately 3,000 children in several countries. These trials showed that vitamin D was associated with an approximately 50 percent reduction in the incidence of tooth decay.
"My main goal was to summarize the clinical trial database so that we could take a fresh look at this vitamin D question," said Dr. Philippe Hujoel of the University of Washington, who conducted the review.
While vitamin D's role in supporting bone health has not been disputed, significant disagreement has historically existed over its role in preventing caries, Hujoel noted. The American Medical Association and the U.S. National Research Council concluded around 1950 that vitamin D was beneficial in managing dental caries. The American Dental Association said otherwise – based on the same evidence. In 1989, the National Research Council, despite new evidence supporting vitamin D's caries-fighting benefits, called the issue "unresolved."
Current reviews by the Institute of Medicine, the U.S. Department of Human Health and Service and the American Dental Association draw no conclusions on the vitamin D evidence as it relates to dental caries.
"Such inconsistent conclusions by different organizations do not make much sense from an evidence-based perspective," Hujoel said. The trials he reviewed increased vitamin D levels in children through the use of supplemental UV radiation or by supplementing the children's diet with cod-liver oil or other products containing the vitamin.
The clinical trials he reviewed were conducted in the United States, Great Britain, Canada, Austria, New Zealand and Sweden. Trials were conducted in institutional settings, schools, medical and dental practices, or hospitals. The subjects were children or young adults between the ages of 2 and 16 years, with a weighted mean age of 10 years.
Hujoel's findings come as no surprise to researchers familiar with past vitamin D studies. According to Dr. Michael Hollick, professor of medicine at the Boston University Medical Center, "the findings from the University of Washington reaffirm the importance of vitamin D for dental health." He said that "children who are vitamin D deficient have poor and delayed teeth eruption and are prone to dental caries."
The vitamin D question takes on greater importance in the light of current public health trends. Vitamin D levels in many populations are decreasing while dental caries levels in young children are increasing.
"Whether this is more than just a coincidence is open to debate," Hujoel said. "In the meantime, pregnant women or young mothers can do little harm by realizing that vitamin D is essential to their offspring's health. Vitamin D does lead to teeth and bones that are better mineralized."
Hujoel added a note of caution to his findings: "One has to be careful with the interpretation of this systematic review. The trials had weaknesses which could have biased the result, and most of the trial participants lived in an era that differs profoundly from today's environment. "
Hujoel has joint appointments as a professor in the University of Washington School of Dentistry's Department of Oral Health Sciences and as an adjunct professor of epidemiology in the UW School of Public Health. His research has concentrated on nutrition with a focus on low-carbohydrate diets, harmful effects of diagnostic radiation, and evidence-based methodology and applications.
His research has also covered sugar substitutes, the use of antibiotics in the treatment of periodontal disease, and cleft lip and cleft palate. He has also studied the link between dental disease and systemic disease, as well as trends in disease prevalence.
Vitamin D prevents clogged arteries in diabetics
People with diabetes often develop clogged arteries that cause heart disease, and new research at Washington University School of Medicine in St. Louis suggests that low vitamin D levels are to blame.
In a study published Nov. 9, 2012 in the Journal of Biological Chemistry, the researchers report that blood vessels are less like to clog in people with diabetes who get adequate vitamin D. But in patients with insufficient vitamin D, immune cells bind to blood vessels near the heart, then trap cholesterol to block those blood vessels.
“About 26 million Americans now have type 2 diabetes,” says principal investigator Carlos Bernal-Mizrachi, MD. “And as obesity rates rise, we expect even more people will develop diabetes. Those patients are more likely to experience heart problems due to an increase in vascular inflammation, so we have been investigating why this occurs.”
In earlier research, Bernal-Mizrachi, an assistant professor of medicine and of cell biology and physiology, and his colleagues found that vitamin D appears to play a key role in heart disease. This new study takes their work a step further, suggesting that when vitamin D levels are low, a particular class of white blood cell is more likely to adhere to cells in the walls of blood vessels.
Vitamin D conspires with immune cells called macrophages either to keep arteries clear or to clog them. The macrophages begin their existence as white blood cells called monocytes that circulate in the bloodstream. But when monocytes encounter inflammation, they are transformed into macrophages, which no longer circulate.
In the new study, researchers looked at vitamin D levels in 43 people with type 2 diabetes and in 25 others who were similar in age, sex and body weight but didn’t have diabetes.
They found that in diabetes patients with low vitamin D — less than 30 nanograms per milliliter of blood — the macrophage cells were more likely to adhere to the walls of blood vessels, which triggers cells to get loaded with cholesterol, eventually causing the vessels to stiffen and block blood flow.
“We took everything into account,” says first author Amy E. Riek, MD, instructor in medicine. “We looked at blood pressure, cholesterol, diabetes control, body weight and race. But only vitamin D levels correlated to whether these cells stuck to the blood vessel wall.”
Riek and Bernal-Mizrachi say what’s not yet clear is whether giving vitamin D to people with diabetes will reverse their risk of developing clogged arteries, a condition called atherosclerosis. They now are treating mice with vitamin D to see whether it can prevent monocytes from adhering to the walls of blood vessels near the heart, and they also are conducting two clinical trials in patients.
In one of those studies, the researchers are giving vitamin D to people with diabetes and hypertension to see whether the treatment may lower blood pressure. In the second study, African Americans with type 2 diabetes are getting vitamin D along with their other daily medications, and the research team is evaluating whether vitamin D supplements can slow or reverse the progression of heart disease.
Sometime in the next several months, the scientists hope to determine whether vitamin D treatment can reverse some of the risk factors associated with cardiovascular disease.
“In the future, we hope to generate medications, potentially even vitamin D itself, that help prevent the deposit of cholesterol in the blood vessels,” Bernal-Mizrachi explains. “Previous studies have linked vitamin D deficiency in these patients to increases in cardiovascular disease and in mortality. Other work has suggested that vitamin D may improve insulin release from the pancreas and insulin sensitivity. Our ultimate goal is to intervene in people with diabetes and to see whether vitamin D might decrease inflammation, reduce blood pressure and lessen the likelihood that they will develop atherosclerosis or other vascular complications.”
Low levels of vitamin D are associated with mortality in older adults
Low levels of vitamin D and high levels of parathyroid hormone are associated with increased mortality in African American and Caucasian older adults, according to a new study accepted for publication in The Endocrine Society's Journal of Clinical Endocrinology and Metabolism (JCEM). The study also indicates that the potential impact of remediating low vitamin D levels is greater in African Americans than Caucasians because vitamin D insufficiency is more common in African Americans.
For the past several years, there has been considerable interest in the role vitamin D plays in improving health and preventing disease. Low levels of vitamin D have been directly associated with various forms of cancer and cardiovascular disease. Most studies regarding the health effects of low vitamin D levels have been conducted on persons of European origin, but the current study examines the relationship between vitamin D and mortality in blacks and whites.
"We observed vitamin D insufficiency (defined as blood levels <20 ng/ml), in one third of our study participants. This was associated with nearly a 50 percent increase in the mortality rate in older adults," said Stephen B. Kritchevsky, PhD, Professor of Internal Medicine and Transitional Science at the Wake Forest School of Medicine, and lead researcher of this study. "Our findings suggest that low levels of vitamin D may be a substantial public health concern for our nation's older adults."
In this study, 2,638 Caucasians and African-Americans aged 70-79 years were asked to fast for 12-hours, after which a blood sample was collected to determine levels of vitamin D. Every six months study participants were contacted to ascertain their medical condition. This study determined the proportion of deaths among participants of with different vitamin D levels. In addition to many health factors, the time of year was also taken into account due to the seasonal effects on vitamin D. Researchers found that levels of vitamin D less than 30 ng/ml were associated with significantly increased all-cause mortality.
"We all know that good nutrition is important to overall health and our study adds to a growing body of literature that underscores the importance of vitamin D and indicates that poor vitamin D nutrition is wide-spread," said Kritchevsky. "The good news is it's easy to improve vitamin D status either through increased skin exposure to sunlight or through diet or supplements."
Vitamin D deficiency increases risk of heart disease
New research from the University of Copenhagen and Copenhagen University Hospital shows that low levels of vitamin D are associated with a markedly higher risk of heart attack and early death. The study involved more than 10,000 Danes and has been published in the well-reputed American journal Arteriosclerosis, Thrombosis and Vascular Biology.
Vitamin D deficiency has traditionally been linked with poor bone health. However, the results from several population studies indicate that a low level of this important vitamin may also be linked to a higher risk of ischemic heart disease, a designation that covers heart attack, coronary arteriosclerosis and angina. Other studies show that vitamin D deficiency may increase blood pressure, and it is well known that high blood pressure increases the risk of heart attack.
"We have now examined the association between a low level of vitamin D and ischemic heart disease and death in the largest study to date. We observed that low levels of vitamin D compared to optimal levels are linked to 40% higher risk of ischemic heart disease, 64% higher risk of heart attack, 57% higher risk of early death, and to no less than 81% higher risk of death from heart disease," says Dr. Peter Brøndum-Jacobsen, Clinical Biochemical Department, Copenhagen University Hospital.
The scientists have compared the 5% lowest levels of vitamin D (less than 15 nanomol vitamin per litre serum) with the 50% highest levels (more than 50 nanomol vitamin per litre serum). In Denmark, it is currently recommended to have a vitamin D status of at least 50 nanomol vitamin per litre serum.
The higher risks are visible, even after adjustment for several factors that can influence the level of vitamin D and the risk of disease and death. This is one of the methods scientists use to avoid bias.
Blood samples from more than 10,000 Danes
The population study that forms the basis for this scientific investigation is the Copenhagen City Heart Study, where levels of vitamin D were measured in blood samples from 1981-1983. Participants were then followed in the nationwide Danish registries up to the present.
"With this type of population study, we are unable to say anything definitive about a possible causal relationship. But we can ascertain that there is a strong statistical correlation between a low level of vitamin D and high risk of heart disease and early death. The explanation may be that a low level of vitamin D directly leads to heart disease and death. However, it is also possible that vitamin deficiency is a marker for poor health generally," says Børge Nordestgaard, clinical professor at the Faculty of Health and Medical Sciences, University of Copenhagen and senior physician at Copenhagen University Hospital.
Long-term goal is prevention
The scientists are now working to determine whether the connection between a low level of vitamin D and the risk of heart disease is a genuine causal relationship.
If this is the case, it will potentially have a massive influence on the health of the world population. Heart disease is the most common cause of adult death in the world according to the World Health Organization (WHO), which estimates that at least 17 million people die every year from heart disease.
"The cheapest and easiest way to get enough vitamin D is to let the sun shine on your skin at regular intervals. There is plenty of evidence that sunshine is good, but it is also important to avoid getting sunburned, which increases the risk of skin cancer. Diet with a good supply of vitamin D is also good, but it has not been proven that vitamin D as a dietary supplement prevents heart disease and death," says Børge Nordestgaard.
The role of vitamin D in critical illness of children
Vitamin D is increasingly being recognized as important for good health. Vitamin D is a hormone made in the skin following sun exposure or acquired from diet and supplement intake. Previous medical research has shown that low body levels of vitamin D make people more susceptible to problems such as bone fractures, poor mental health and infections like the common cold. Until recently, there had been little consideration given to the role of vitamin D in more severe diseases, which is why Dr. Dayre McNally's recent publication in the esteemed scientific journal Pediatrics is so compelling.
"This is the first study to report on vitamin D levels in a large group of critically ill children," said Dr. McNally, a clinical researcher and intensivist at the Children's Hospital of Eastern Ontario (CHEO) and assistant professor in the Department of Pediatrics at the University of Ottawa.
The study, led by Dr. McNally at the CHEO Research Institute, included over 300 children and teenagers at six hospitals in Ottawa, Toronto, Hamilton, Edmonton, Saskatoon and Vancouver. These children were admitted to an Intensive Care Unit (ICU) with severe infections, significant trauma or conditions requiring major surgery, such as congenital heart defects.
Their study found that in three of every four critically ill children, blood vitamin D levels were below the target considered safe by many experts and medical societies. Further, those with lower vitamin D levels were noted to be sicker, requiring more life-sustaining therapies (breathing tubes, medications to support heart function) and staying in the ICU for longer periods of time.
"Although these findings are of concern, we are very encouraged because we've discovered something that is modifiable," explained Dr. McNally. "There are simple ways to prevent this problem, and it may be possible to rapidly restore vitamin D levels at the time of severe illness."
Low levels of vitamin D can mean a much greater risk of death.
A new study concludes that among older adults – especially those who are frail – low levels of vitamin D can mean a much greater risk of death.
The randomized, nationally representative study found that older adults with low vitamin D levels had a 30 percent greater risk of death than people who had higher levels.
Overall, people who were frail had more than double the risk of death than those who were not frail. Frail adults with low levels of vitamin D tripled their risk of death over people who were not frail and who had higher levels of vitamin D.
“What this really means is that it is important to assess vitamin D levels in older adults, and especially among people who are frail,” said lead author Ellen Smit of Oregon State University.
Smit said past studies have separately associated frailty and low vitamin D with a greater mortality risk, but this is the first to look at the combined effect. This study, published online in the European Journal of Clinical Nutrition, examined more than 4,300 adults older than 60 using data from the Third National Health and Nutrition Examination Survey.
“Older adults need to be screened for vitamin D,” said Smit, who is a nutritional epidemiologist at OSU’s College of Public Health and Human Sciences. Her research is focused on diet, metabolism, and physical activity in relation to both chronic disease and HIV infection.
“As you age, there is an increased risk of melanoma, but older adults should try and get more activity in the sunshine,” she said. “Our study suggests that there is an opportunity for intervention with those who are in the pre-frail group, but could live longer, more independent lives if they get proper nutrition and exercise.”
Frailty is when a person experiences a decrease in physical functioning characterized by at least three of the following five criteria: muscle weakness, slow walking, exhaustion, low physical activity, and unintentional weight loss. People are considered “pre-frail” when they have one or two of the five criteria.
Because of the cross-sectional nature of the survey, researchers could not determine if low vitamin D contributed to frailty, or whether frail people became vitamin D deficient because of health problems. However, Smit said the longitudinal analysis on death showed it may not matter which came first.
“If you have both, it may not really matter which came first because you are worse off and at greater risk of dying than other older people who are frail and who don’t have low vitamin D,” she said. “This is an important finding because we already know there is a biological basis for this. Vitamin D impacts muscle function and bones, so it makes sense that it plays a big role in frailty.”
The study divided people into four groups. The low group had levels less than 50 nanomole per liter; the highest group had vitamin D of 84 or higher. In general, those who had lower vitamin D levels were more likely to be frail.
About 70 percent of Americans, and up to a billion people worldwide, have insufficient levels of vitamin D. And during the winter months in northern climates, it can be difficult to get enough just from the sun. OSU’s Linus Pauling Institute recommends adults take 2,000 IU of supplemental vitamin D daily. The current federal guidelines are 600 IU for most adults, and 800 for those older than 70.
“We want the older population to be able to live as independent for as long as possible, and those who are frail have a number of health problems as they age,” Smit said. “A balanced diet including good sources of vitamin D like milk and fish, and being physically active outdoors, will go a long way in helping older adults to stay independent and healthy for longer.”
Vitamin D may protect against lung function impairment and decline in smokers
Vitamin D deficiency is associated with worse lung function and more rapid decline in lung function over time in smokers, suggesting that vitamin D may have a protective effect against the effects of smoking on lung function, according to a new study from researchers in Boston.
"We examined the relationship between vitamin D deficiency, smoking, lung function, and the rate of lung function decline over a 20 year period in a cohort of 626 adult white men from the Normative Aging Study," said lead author Nancy E. Lange, MD, MPH, of the Channing Laboratory, Brigham and Women's Hospital. "We found that vitamin D sufficiency (defined as serum vitamin D levels of >20 ng/ml) had a protective effect on lung function and the rate of lung function decline in smokers."
The findings were published online ahead of print publication in the American Thoracic Society's American Journal of Respiratory and Critical Care Medicine.
In the study, vitamin D levels were assessed at three different time points between 1984 and 2003, and lung function was assessed concurrently with spirometry.
In vitamin D deficient subjects, for each one unit increase in pack-years of smoking, mean forced expiratory volume in one second (FEV1) was 12 ml lower, compared with a mean reduction of 6.5 ml among subjects who were not vitamin D deficient. In longitudinal models, vitamin D deficiency exacerbated the effect of pack years of smoking on the decline in FEV1 over time.
No significant effect of vitamin D levels on lung function or lung function decline were observed in the overall study cohort, which included both smokers and non-smokers.
"Our results suggest that vitamin D might modify the damaging effects of smoking on lung function," said Dr. Lange. "These effects might be due to vitamin D's anti-inflammatory and anti-oxidant properties."
The study has some limitations, including that the data is observational only and not a trial, that vitamin D levels fluctuate over time, and that the study has limited generalizability due to the cohort being all elderly men.
"If these results can be replicated in other studies, they could be of great public health importance," said Dr. Lange. "Future research should also examine whether vitamin D protects against lung damage from other sources, such as air pollution."
"While these results are intriguing, the health hazards associated with smoking far outweigh any protective effect that vitamin D may have on lung function ," said Alexander C. White MS, MD, chair of the American Thoracic Society's Tobacco Action Committee. "First and foremost, patients who smoke should be fully informed about the health consequences of smoking and in addition be given all possible assistance to help them quit smoking."
Pancreatic Cancer Risk Lowered By Exposure To Sun
According to a study presented by Rachel Neale, Ph.D. at the American Association for Cancer Research's Pancreatic Cancer: Progress and Challenges conference in June, 2012, the risk of pancreatic cancer is decreased in individuals with a history of skin cancer, as well as in those born in a location with high levels of ultraviolet radiation and in people whose skin is sensitive to sun.
Rachel Neale, Ph.D., from Australia's Queensland Institute of Medical Research led the population-based, case-control study, which adds to existing conflicting data about sun exposure, vitamin D gained from sun exposure and the risk of cancer. Neale's study results support existing ecological data, which suggests that sun exposure has a protective effect against pancreatic cancer.
"Several ecological studies, including one conducted in Australia, have suggested that people living in areas with high sun exposure have lower risk for pancreatic cancer. However, some studies of circulating vitamin D indicate that people with high vitamin D are at increased risk, and one study of vitamin D intake supports this increased risk."
The study was conducted between 2007 and 2011 and involved 714 Australians from Queensland, who were matched to 709 controls in terms of age and sex. The team questioned all participants regarding their socio-demographic information and medical history, as well as about their birth location, history of skin cancer and skin type in terms of skin color, risk of sunburn sunburn and tanning ability.
The team then assigned the appropriate ultraviolet radiation level to each birth location using NASA's Total Ozone Mapping Spectrometer, and divided them into three categories based on the level of radiation.
They found that the risk for pancreatic cancer was 24% lower in those born in areas with the highest levels of ultraviolet radiation as compared with those born in areas of low ultraviolet radiation.
Despite the fact that all skin types have a considerable link of being at risk for pancreatic cancer, they discovered that those with the most sun-sensitive skin had a 49% lower risk than those with the least sun-sensitive skin. In addition, the risk of pancreatic cancer was 40% lower in participants with a history of skin cancer or other sun-related skin lesions compared with those who had not reported skin lesions.
"There is increasing interest in the role of sun exposure, which has been largely attributed to the effect of vitamin D, on cancer incidence and mortality. It is important that we understand the risks and benefits of sun exposure because it has implications for public health messages about sun exposure, and possibly about policy related to vitamin D supplementation or food fortification."
Neale suggests that large cohort studies are needed in the future, which measure sun exposure and vitamin D levels more comprehensively. She concludes: "There are several trials of vitamin D that are either under way or planned, and pooling data from these might give some clue about vitamin D and pancreatic cancer."
Vitamin D Supplementation Effective In Fracture Risk Reduction In Older Adults
Based on the results of a pooled analysis of 11 unrelated randomized clinical trials investigating vitamin D supplementation and fracture risk in more than 31,000 older adults, Bess Dawson-Hughes, MD, director of the Bone Metabolism Laboratory at the Jean Mayer USDA Human Nutrition Research Center on Aging (USDA HNRCA) at Tufts University, says higher doses of Vitamin D may be the most beneficial in reducing bone fractures in this age group.
As part of the study, published in The New England Journal of Medicine, Dawson-Hughes and colleagues divided the subjects into quartiles ranging from 0 to 2,000 International Units (IUs) of daily vitamin D intake. The top quartile sustained 30% fewer hip fractures and 14% fewer fractures of other bones compared to the control groups.
"Taking between 800 IUs and 2,000 IUs of vitamin D per day significantly reduced the risk of most fractures, including hip, wrist and forearm in both men and women age 65 and older," said Dawson-Hughes, the study's senior author. "Importantly, we saw there was no benefit to taking Vitamin D supplements in doses below 800 IUs per day for fracture prevention."
Dawson-Hughes and colleagues analyzed each participant's vitamin D supplementation within and independent of the study protocol, controlling for age, vitamin D blood levels at baseline, additional calcium supplementation and whether the person lived independently or under medical care.
"Evaluation of individual-level data is the gold-standard of meta-analysis," said lead author Heike Bischoff-Ferrari, MD, D.Ph., director of the Centre on Aging and Mobility at the University of Zurich and Waid City Hospital and a visiting scientist in the Bone Metabolism Laboratory at the USDA HNRCA. "Our results make a compelling contribution to the existing data on Vitamin D and fracture risk in men and women age 65 and older, whose vulnerability to bone density loss and osteoporosis leave them prone to fractures resulting from thinning bones."
The current Dietary Reference Intake (DRI) for vitamin D in older adults set by the Institute of Medicine (IOM) is a minimum of 600 IUs per day for adults between 51 and 70 years-old and 800 IUs in adults over 70.
"Vitamin D supplementation is an efficient intervention for a costly injury that affects thousands of older adults each year," said Dawson-Hughes, who is also a professor at Tufts University School of Medicine. "The average recovery is long and painful and deeply impacts quality of life. After a fracture, older patients may only regain partial mobility, resulting in a loss of independence that is personally demoralizing and that can place added stress on family members and caregivers"
Financially, Vitamin D supplements cost pennies a day, Dawson-Hughes said, whereas the American Academy of Orthopaedic Surgeons estimated the cost of treating a hip fracture was $26,912 in 2007.
Dawson-Hughes adds that older adults, unless they are exposed to bright, year-round sunlight, require supplementation to meet their vitamin D needs. Typically, adults consume 150 IUs per day from food sources such as tuna or salmon or fortified milk. On average, multivitamins contain 400 IUs of vitamin D and there are individual vitamin D supplements with 400, 800 or 1,000 IUs. While vitamin D toxicity is rare, the IOM suggests capping intake at 4,000 IUs per day.
Dawson-Hughes said the results of the current study would be strengthened by large interventional trials investigating the impact of vitamin D supplementation on fracture risk. She and the authors also call for further investigation of the impact of combining calcium supplementation with high doses of vitamin D, as their data was inconclusive.
Vitamin D's Potential to Reduce the Risk of Hospital-Acquired Infections
A paper recently published in Dermato-Endocrinology [Youssef et al., 2012] indicates that raising vitamin D concentrations among hospital patients has the potential to greatly reduce the risk of hospital-acquired infections. Hospital-acquired infections (HAIs) are a leading cause of death in the US health care arena, with an overall estimated annual incidence of 1.7 million cases and 100,000 deaths. HAIs in US hospitals generate an estimated $28.4 billion–$45 billion in excess health care costs annually. Patients are often vitamin D deficient since many diseases such as cancer, cardiovascular disease, and respiratory infections are linked to low vitamin D concentrations.
Pneumonia is the most likely HAI, followed by bacteremias, urinary tract infections, surgical site infections, sepsis, and others.
Vitamin D plays an important antimicrobial role. Among the antimicrobial actions are reducing local and systemic inflammatory responses as a result of modulating cytokine responses and reducing Toll-like receptor activation and stimulating the expression of potent antimicrobial peptides, such as cathelicidin and _-defensin 2. Cathelicidins are a family of peptides thought to provide an innate defensive barrier against a variety of potential microbial pathogens, such as gram-positive and gram-negative bacteria, fungi, and mycobacteria, at multiple entry sites, including skin and mucosal linings of the respiratory and gastrointestinal systems, as well as some viruses.
One of the advantages of vitamin D in combating HAIs is that it strengthens the innate immune response, thus overcoming the antibiotic resistance of many bacteria encountered in hospitals.
Optimal vitamin D concentrations are at least 30-40 ng/ml (75-100 nmol/l). The average white American has a concentration of 26 ng/ml, while the average African-American has only 16 ng/ml. Vitamin D concentrations have fallen in the past 20 years, in part due to spending less time out-of-doors. About half of those admitted to hospitals have concentrations below 20 ng/ml, thus making them more susceptible to HAIs. Raising vitamin D concentrations would reduce the rate of diseases such as many types of cancer, cardiovascular disease, hip fractures, and respiratory infections, thereby reducing the rate of hospital admissions as well as HAIs once admitted.
In an accompanying editorial, David McCarthy, M.D. outlined what hospitals could do to overcome vitamin D deficiency among hospital patients. Among these recommendations is making high-dose vitamin D3 (5,000 and 50,000 IU) capsules available to the patients.
Low vitamin D level is linked to greater chance of risk factors for Type 2 diabetes
A new study presents more evidence of a possible link between low vitamin D levels and a higher risk of Type 2 diabetes and heart disease. The results were presented at The Endocrine Society's 94th Annual Meeting (2012) in Houston.
The study found an inverse relationship between the level of vitamin D in the blood and the presence of the metabolic syndrome, which is a group of risk factors that increases the risk of heart disease and Type 2 diabetes. People with the highest blood levels of vitamin D had a 48 percent lower risk of having the metabolic syndrome than did those with the lowest vitamin D levels, the authors reported.
"This association has been documented before, but our study expands the association to people of diverse racial and ethnic backgrounds," said the lead author, Joanna Mitri, MD, a research fellow at Tufts Medical Center in Boston. "These include minority groups that are already at higher risk of diabetes."
Furthermore, all study participants were at risk of developing diabetes because they had prediabetes, abnormally high blood sugar levels that are not yet high enough to be classified as diabetes. Prediabetes affects an estimated 79 million Americans ages 20 or older, according to 2010 statistics from the Centers for Disease Control and Prevention.
Mitri and her co-investigators conducted the study using data from participants of the Diabetes Prevention Program, a large, now-completed study funded by the National Institutes of Health. They divided study subjects into three groups based on plasma 25-hydroxyvitamin D level, which is the most common way used to measure vitamin D status in the body, according to Mitri. The Institute of Medicine recommends a 25-hydroxyvitamin D level of 20 to 30 ng/mL as adequate for healthy people.
In the new study, the group with the highest levels of vitamin D had a median vitamin D concentration of 30.6 nanograms per milliliter, or ng/mL, and those in the lowest group had a median vitamin D concentration of 12.1 ng/mL. The risk of having the metabolic syndrome with a high vitamin D level was about one half the risk with a low vitamin D level, Mitri said.
The researchers also found an association between vitamin D status and some of the individual components of the metabolic syndrome, which includes a large waist size, low HDL ("good") cholesterol, high triglycerides (fats in the blood), high blood pressure and high blood glucose (sugar). Study participants with the best vitamin D status had a smaller waist circumference, higher HDL cholesterol and lower blood sugar.
Mitri cautioned that their research does not prove that vitamin D deficiency causes Type 2 diabetes, or even that there is a link between the two conditions.
"However, the metabolic syndrome is common, and progression to Type 2 diabetes is high," she said. "If a causal relationship can be established in ongoing and planned studies of vitamin D, this link will be of public health importance, because vitamin D supplementation is easy and inexpensive."
Treating vitamin D deficiency may improve depression
Women with moderate to severe depression had substantial improvement in their symptoms of depression after they received treatment for their vitamin D deficiency, a new study finds. The case report series was presented at The Endocrine Society's 94th Annual Meeting (2012) in Houston.
Because the women did not change their antidepressant medications or other environmental factors that relate to depression, the authors concluded that correction of the patients' underlying shortage of vitamin D might be responsible for the beneficial effect on depression.
"Vitamin D may have an as-yet-unproven effect on mood, and its deficiency may exacerbate depression," said Sonal Pathak, MD, an endocrinologist at Bayhealth Medical Center in Dover, Del. "If this association is confirmed, it may improve how we treat depression."
Pathak presented the research findings in three women, who ranged in age from 42 to 66. All had previously diagnosed major depressive disorder, also called clinical depression, and were receiving antidepressant therapy. The patients also were being treated for either Type 2 diabetes or an underactive thyroid (hypothyroidism).
Because the women had risk factors for vitamin D deficiency, such as low vitamin D intake and poor sun exposure, they each underwent a 25-hydroxyvitamin D blood test. For all three women, the test found low levels of vitamin D, ranging from 8.9 to 14.5 nanograms per milliliter (ng/mL), Pathak reported. Levels below 21 ng/mL are considered vitamin D deficiency, and normal vitamin D levels are above 30 ng/mL, according to The Endocrine Society.
Over eight to 12 weeks, oral vitamin D replacement therapy restored the women's vitamin D status to normal. Their levels after treatment ranged from 32 to 38 ng/mL according to the study abstract.
After treatment, all three women reported significant improvement in their depression, as found using the Beck Depression Inventory. This 21-item questionnaire scores the severity of sadness and other symptoms of depression. A score of 0 to 9 indicates minimal depression; 10 to 18, mild depression; 19 to 29, moderate depression; and 30 to 63, severe depression.
One woman's depression score improved from 32 before vitamin D therapy to 12, a change from severe to mild depression. Another woman's score fell from 26 to 8, indicating she now had minimal symptoms of depression. The third patient's score of 21 improved after vitamin D treatment to 16, also in the mild range.
Other studies have suggested that vitamin D has an effect on mood and depression, but there is a need for large, good-quality, randomized controlled clinical trials to prove whether there is a real causal relationship, Dr Pathak said.
"Screening at-risk depressed patients for vitamin D deficiency and treating it appropriately may be an easy and cost-effective adjunct to mainstream therapies for depression," she said.
Vitamin D and Erectile Dysfunction
A paper recently published (Sorenson M, Grant W. Does vitamin D deficiency contribute to erectile dysfunction?. Dermato-Endocrinology 2012; 4:128 - 136; http://dx.doi.org10.4161/derm.20361. ) hypothesizes that vitamin D deficiency may be an important risk factor for erectile dysfunction (ED). Evidence cited supporting the link between low vitamin D and ED include that those with Asthma, depression, falls and fractures, multiple sclerosis, and periodontal disease are at greater risk of having ED. In addition, those with ED are at greater risk of developing cardiovascular disease, diabetes mellitus, and metabolic syndrome. All of these diseases are linked to vitamin D deficiency.
Vascular problems account for about half the cases of ED. There is a large body of research finding that vitamin D can maintain vascular health. The mechanisms appear to include suppressing the activity of the renin-angiotensin system, thereby lowering blood pressure, improving endothelial function, reducing inflammation, and reducing vascular calcification. Solar ultraviolet (UV) light is the primary source of vitamin D for most people. In addition, UV increases nitric oxide concentrations in the blood, which also appears to reduce the risk of ED.
Those diagnosed with ED should consider having serum 25-hydroxyvitamin D [25(OH)D] concentration measured, then adopt a program to increase concentrations to at least 40 ng/ml (100 nmol/l) through vitamin D supplementation and/or increased solar UVB exposure. Serum 25(OH)D concentrations should be re-measured a few months after starting such a program.
Those diagnosed with ED should also have their physician check for signs of early diabetes or cardiovascular disease.
According to Dr. Richard Quinton, Consultant Physician (endocrinologist), The Newcastle upon Tyne Hospitals, England:“Onset of erectile dysfunction is a life-changing event for a man of any age. Fortunately, there are now reasonably successful medical treatments for it. However, as he or she is signing the script, the Physician should remember that ED is frequently an early indicator of systemic disease. The conditions we tend to think of first in relation to ED are diabetes and hypogonadism, but any occult systemic disease can precipitate ED many years before it becomes clinically apparent.
The hypothesis presented in this paper is certainly plausible and deserves to be tested, but even if there turns out to be no direct vascular-related link between ED and hypovitaminosis D, it is highly likely that patients with symptomatic fatigue and/or musculoskeletal aches and pains secondary to the more severe end of the hypovitaminosis D spectrum will exhibit impaired erectile and sexual function.
“We know from the MRC survey that severe hypovitaminosis D is highly-prevalent even among middle-aged Caucasians in the UK, particularly in the West of Scotland. This is almost certainly due to our high latitude, prevalent cloud cover and low fish consumption. So, whilst writing that script for erection-promoting tablet, the Physician should also consider the possibility of hypovitaminosis D, particularly if the following risk factors are present: constitutively darker skin type, conscious or unconscious sun-avoidance behaviour, including culturally or behaviourally-determined forms of clothing, routine use of SPF sunblock in everyday life, shift work, obesity, medication with immunosuppressants or anticonvulsants, or bowel disease predisposing to fat soluble vitamin malabsorbtion.
“Thus, among the lifestyle changes the Physician might typically promote in the context of ED, such as “stop smoking, take more exercise, eat more healthily and lose weight”, “get more sunshine exposure to bare skin” should perhaps also be in the mix. For the purpose of maximising vitamin D photosynthesis, whilst minimising solar skin damage, the mathematically most logical solution is to expose as much skin as possible (without burning) -ie. sunbathing- rather than just exposing forearms, face and neck for a longer period. “However, we all know how hard it is to persuade our patients to make significant and sustained lifestyle changes, which is precisely why bariatric surgery has taken off in recent years. Moreover, not everyone can afford to take a “winter sun” holiday, so for many people, taking an oral vitamin D supplement may be the way forward.”
According to Dr. Stefan Pilz, Department of Internal Medicine, Division of Endocrinology and Metabolism, Medical University of Graz, Graz, Austria: "Vitamin D deficiency is associated with various risk factors for erectile dysfunction as reviewed by Marc Sorenson and William B. Grant. A role of vitamin D deficiency in the pathogenesis of erectile dysfunction can be hypothesized. Randomized controlled trials should therefore evaluate whether vitamin D supplementation exerts relevant effects with regard to erectile dysfunction."
According to Marc Sorenson, director of the Sunlight Institute and lead author, “The treatment of choice for ED has been the use of phosphodiesterase-5 inhibitors such as Viagra. While effective in relieving the ED symptoms, these drugs do nothing for the underlying cause and may lose their effectiveness over time. They may also hide from users the possibility of cardiovascular disease; therefore patients may delay seeking help. If proven in further research, vitamin D optimization has the potential to influence the cause of ED to prevent or mitigate the condition.”
According to William B. Grant, Ph.D., director of Sunlight, Nutrition and Health Research Center, a coauthor:_“This paper is the first to hypothesize a link between erectile dysfunction and vitamin D deficiency. While it is not clear what role increasing vitamin D concentrations to 40 ng/ml (100 nmol/l) will have on erectile dysfunction, it will reduce the risk of diabetes, cardiovascular disease, many types of cancer, and several infectious diseases. Thus, a diagnosis of erectile dysfunction not due to prostate surgery or psychological state should be considered a wakeup call to investigate the roles of solar UVB and vitamin D for improving overall health.”
Vitamin D3 supplements better
New research funded by the Biotechnology and Biological Sciences Research Council (BBSRC) has shown that vitamin D3 supplements could provide more benefit than the close relative vitamin D2. The findings published in the June edition of the American Journal of Clinical Nutrition could potentially lead to changes in the food industry when it comes to fortification.
Vitamin D is important for bone and muscle health and there is concern that we don't get enough of the 'sunshine' vitamin through exposure to sunlight or through diet. As a result, some foods are fortified with vitamin D. Fortification is usually with vitamin D2, as this is not derived from animals. However this new research, carried out by scientists from the University of Surrey, suggests that vitamin D3 is the more beneficial of the two types of vitamin D in raising the vitamin D levels in our blood when given as a supplement.
The research clearly showed that vitamin D3, the type of vitamin D found in foods including eggs and oily fish, is more effectively converted by the body into the hormone responsible for health benefits in humans.
Dr Laura Tripkovic, who led the study, explains: "We know that vitamin D is vital in helping to keep us fit and healthy, but what has not been clear is the difference between the two types of vitamin D. It used to be thought that both were equally beneficial, however our analysis highlights that our bodies may react differently to both types and that vitamin D3 could actually be better for us."
The researchers analysed the results of 10 separate studies, involving over 1,000 people in total, comparing the health benefits of vitamin D2 and D3, and found "a clear favouring" of vitamin D3 supplements raising vitamin D serum levels in humans.
Older Adults May Need More Vitamin D to Prevent Mobility Difficulties
Older adults who don't get enough vitamin D - either from diet, supplements or sun exposure - may be at increased risk of developing mobility limitations and disability, according to new research from Wake Forest Baptist Medical Center.
"This is one of the first studies to look at the association of vitamin D and the onset of new mobility limitations or disability in older adults," said lead author Denise Houston, Ph.D., R.D., a nutrition epidemiologist in the Wake Forest Baptist Department of Geriatrics and Gerontology. Houston researches vitamin D and its effects on physical function.
The study, published online (May, 2012) in the Journal of Gerontology: Medical Sciences, analyzed the association between vitamin D and onset of mobility limitation and disability over six years of follow-up using data from the National Institute on Aging's Health, Aging, and Body Composition (Health ABC) study. Mobility limitation and disability are defined as any difficulty or inability to walk several blocks or climb a flight of stairs, respectively.
Of the 3,075 community-dwelling black and white men and women aged 70-79 who were enrolled, data from 2,099 participants was used for this study. Eligible participants reported no difficulty walking one-fourth mile, climbing 10 steps, or performing basic, daily living activities, and were free of life-threatening illness. Vitamin D levels were measured in the blood at the beginning of the study. Occurrence of mobility limitation and disability during follow-up was assessed during annual clinic visits alternating with telephone interviews every six months over six years.
"We observed about a 30 percent increased risk of mobility limitations for those older adults who had low levels of vitamin D, and almost a two-fold higher risk of mobility disability," Houston said.
Houston said vitamin D plays an important role in muscle function, so it is plausible that low levels of the vitamin could result in the onset of decreased lower muscle strength and physical performance. Vitamin D may also indirectly affect physical function as low vitamin D levels have also been associated with diabetes, high blood pressure, cardiovascular disease and lung disease - conditions that are frequent causes of decline in physical function. Houston said people get vitamin D when it is naturally produced in the skin by sun exposure, by eating foods with vitamin D, such as fortified milk, juice and cereals, and by taking vitamin D supplements.
"About one-third of older adults have low vitamin D levels," she said. "It's difficult to get enough vitamin D through diet alone and older adults, who may not spend much time outdoors, may need to take a vitamin D supplement."
Current recommendations call for people over age 70 to get 800 International Units of vitamin D daily in their diet or supplements. Houston pointed out that current dietary recommendations are based solely on vitamin D's effects on bone health.
"Higher amounts of vitamin D may be needed for the preservation of muscle strength and physical function as well as other health conditions," she said. "However, clinical trials are needed to determine whether increasing vitamin D levels through diet or supplements has an effect on physical function."
Oral Vitamin D Supplements Fight Prostate Cancer
Higher oral doses of plain vitamin D raised levels of calcitriol in prostate tissue. Higher prostate levels of calcitriol, a hormone made from vitamin D, corresponded with lower levels of the proliferation marker Ki67 and increased levels of cancer growth-inhibitory microRNAs in prostate cancer cells.
The results not only point to the mechanisms by which vitamin D affects the rate of prostate cancer growth, but also indicate that vitamin D may slow the growth of prostate cancer cells — a key finding given that the role of vitamin D in prostate cancer has been “controversial, with some suggesting that higher levels of vitamin D should be avoided,” said Reinhold Vieth, Ph.D., professor at the University of Toronto in Toronto, Ontario, Canada.
“This study shows calcitriol makes the foot come off the gas pedal of cancer growth. We are not able to prove that the speed of the car has slowed down, but it certainly is a good sign,” said Vieth. “We expect that this early-phase clinical trial will open the door for more detailed clinical research into the usefulness of vitamin D in the treatment or prevention of prostate cancer.”
Vieth and colleagues previously reported that in men who were being monitored regularly for prostate cancer, higher vitamin D levels slowed the rate of rise in prostate-specific antigen levels. They randomly assigned 66 men scheduled for radical prostatectomy to daily vitamin D in doses of 400, 10,000 or 40,000 IU for three to eight weeks before surgery. Researchers found that calcitriol levels in the prostate increased progressively with each daily dose of vitamin D, with 40,000 IU showing the highest levels. These higher levels of calcitriol corresponded with lower prostate levels of Ki67, a protein that indicates prostate cancer cell growth, as well as higher levels of specific growth-inhibitory microRNAs.
Vieth stressed that he and his colleagues do not advocate vitamin D supplementation in doses higher than 4,000 IU daily. Patients were assigned to the 40,000 IU daily dose because of the short presurgical time frame available for study, not as a regular regimen.
“Plain vitamin D provides the raw material to permit the body to take care of its own needs,” he said. “We showed here that plain vitamin D allows the prostate to regulate its own level of calcitriol, and at the doses we used, for the time frame we used, it has been safe with the hoped-for desirable outcomes.”
Vitamin D deficiency linked to higher mortality in female nursing home residents
The majority of institutionalized elderly female patients are vitamin D deficient and there is an inverse association of vitamin D deficiency and mortality, according to a recent study accepted for publication in The Endocrine Society's Journal of Clinical Endocrinology and Metabolism (JCEM).
Recommendations for dietary vitamin D intake in the elderly are higher than any other age group because vitamin D deficiency is extraordinarily prevalent in this population and is considered a causal risk factor for skeletal diseases. Treatment involves the daily ingestion of up to 800 IU of vitamin D. The current study examined whether vitamin D deficiency is an independent risk factor for mortality in institutionalized elderly patients.
"Our findings show that the vast majority of nursing home residents are severely vitamin D deficient and those with the lowest vitamin D levels are at high risk of mortality," said Dr. Stefan Pilz, MD, of the Medical University of Graz, Austria, and lead author of the study. "This situation warrants immediate action to prevent and treat vitamin D deficiency."
In this study, researchers examined a sample of 961 nursing home residents in Austria, with an average age of 83.7 years. The researchers recorded 284 deaths—or 30 percent of the study cohort—after a mean follow-up time of 27 months. Their findings showed that vitamin D levels were below recommended levels in 92.8 percent of the study participants, suggesting that while vitamin D deficiency among frail and elderly populations has been acknowledged for several decades, no effective strategies to treat the deficiencies have been developed and implemented.
"Vitamin D supplementation in these patients can exert significant benefits on clinically relevant outcomes such as fractures," said Pilz. "In light of our findings, and the existing literature on adverse effects of vitamin D deficiency, there exists now an urgent need for effective strategies to improve vitamin D status in older institutionalized patients.
Vitamin D may help clear amyloid plaques found in Alzheimer's
A team of academic researchers has identified the intracellular mechanisms regulated by vitamin D3 that may help the body clear the brain of amyloid beta, the main component of plaques associated with Alzheimer's disease.
Published in the March 6, 2012 issue of the Journal of Alzheimer's Disease, the early findings show that vitamin D3 may activate key genes and cellular signaling networks to help stimulate the immune system to clear the amyloid-beta protein.
Previous laboratory work by the team demonstrated that specific types of immune cells in Alzheimer's patients may respond to therapy with vitamin D3 and curcumin, a chemical found in turmeric spice, by stimulating the innate immune system to clear amyloid beta. But the researchers didn't know how it worked.
"This new study helped clarify the key mechanisms involved, which will help us better understand the usefulness of vitamin D3 and curcumin as possible therapies for Alzheimer's disease," said study author Dr. Milan Fiala, a researcher at the David Geffen School of Medicine at UCLA and the Veterans Affairs Greater Los Angeles Healthcare System.
For the study, scientists drew blood samples from Alzheimer's patients and healthy controls and then isolated critical immune cells from the blood called macrophages, which are responsible for gobbling up amyloid beta and other waste products in the brain and body.
The team incubated the immune cells overnight with amyloid beta. An active form of vitamin D3 called 1a,25–dihydroxyvitamin D3, which is made in the body by enzymatic conversion in the liver and kidneys, was added to some of the cells to gauge the effect it had on amyloid beta absorption.
Previous work by the team, based on the function of Alzheimer's patients' macrophages, showed that there are at least two types of patients and macrophages: Type I macrophages are improved by addition of 1a,25–dihydroxyvitamin D3 and curcuminoids (a synthetic form of curcumin), while Type II macrophages are improved only by adding 1a,25–dihydroxyvitamin D3.
Researchers found that in both Type I and Type II macrophages, the added 1a,25–dihydroxyvitamin D3 played a key role in opening a specific chloride channel called "chloride channel 3 (CLC3)," which is important in supporting the uptake of amyloid beta through the process known as phagocytosis. Curcuminoids activated this chloride channel only in Type I macrophages.
The scientists also found that 1a,25–dihydroxyvitamin D3 strongly helped trigger the genetic transcription of the chloride channel and the receptor for 1a,25–dihydroxyvitamin D3 in Type II macrophages. Transcription is the first step leading to gene expression.
The mechanisms behind the effects of 1a,25–dihydroxyvitamin D3 on phagocytosis were complex and dependent on calcium and signaling by the "MAPK" pathway, which helps communicate a signal from the vitamin D3 receptor located on the surface of a cell to the DNA in the cell's nucleus.
The pivotal effect of 1a,25–dihydroxyvitamin D3 was shown in a collaboration between Dr. Patrick R. Griffin from the Scripps Research Institute and Dr. Mathew T. Mizwicki from UC Riverside. They utilized a technique based on mass spectrometry, which showed that 1a,25–dihydroxyvitamin D3 stabilized many more critical sites on the vitamin D receptor than did the curcuminoids.
"Our findings demonstrate that active forms of vitamin D3 may be an important regulator of immune activities of macrophages in helping to clear amyloid plaques by directly regulating the expression of genes, as well as the structural physical workings of the cells," said study author Mizwicki, who was an assistant research biochemist in the department of biochemistry at UC Riverside when the study was conducted.
According to the team, one of the next stages of research would be a clinical trial with vitamin D3 to assess the impact on Alzheimer's disease patients. Previous studies by other teams have shown that a low serum level of 25–hydroxyvitamin D3 may be associated with cognitive decline. It is too early to recommend a definitive dosage of vitamin D3 to help with Alzheimer's disease and brain health, the researchers said. They add that ongoing studies are showing that vitamin D3 may be beneficial in reducing the incidence of a growing number of human diseases.
Vitamin D intake may be associated with lower stress fracture risk in girls
Vitamin D may be associated with a lower risk of developing stress fractures in preadolescent and adolescent girls, especially among those very active in high-impact activities, according to a report published Online First by Archives of Pediatrics & Adolescent Medicine, one of the JAMA/Archives journals.
Stress fractures, a relatively common sports-related injury, occur when stresses on a bone exceed its capacity to withstand and heal from those forces. But while consumption of calcium and calcium-rich dairy produ cts is routinely encouraged for optimal bone health, researchers note in their study background that the evidence for this recommendation has been challenged.
Kendrin R. Sonneville, Sc.D., R.D., of Children's Hospital Boston, and colleagues conducted a study to identify whether calcium, vitamin D and/or the intake of dairy were prospectively associated with stress fracture risk among girls. The study included 6,712 preadolescent and adolescent girls (age 9 to 15 at baseline) in the Growing Up Today Study.
During seven years of follow-up, 3.9 percent of the girls developed a stress fracture. Dairy and calcium intakes were unrelated to risk of developing a stress fracture. However, vitamin D intake was associated with a lower risk of developing a stress fracture, particularly among those girls who participate in at least one hour a day of high-impact activity.
"In contrast, there was no evidence that calcium and dairy intakes were protective against developing a stress fracture or that soda intake was predictive of an increased risk of stress fracture or confounded the association between dairy, calcium or vitamin D intakes and fracture risk," the authors comment.
The authors also note that in a stratified analysis that high calcium intake was associated with a greater risk of developing a stress fracture, although they suggest that "unexpected finding" warrants more study.
The authors conclude their findings support the Institute of Medicine's recent increase in the recommended dietary allowance for vitamin D for adolescents from 400 IU/d to 600 IU/d.
"Further studies are needed to ascertain whether vitamin D intake from supplements confers a similarly protective effect as vitamin D consumed through dietary intake," they comment.
Sunshine may help to prevent allergies and eczema
Increased exposure to sunlight may reduce the risk of both food allergies and eczema in children, according to a new scientific study .
Researchers from the European Centre for Environment & Human Health, along with several Australian institutions, have found that children living in areas with lower levels of sunlight are at greater risk of developing food allergies and the skin condition eczema, compared to those in areas with higher UV.
The research team used data from a study of Australian children and analysed how rates of food allergy, eczema and asthma varied throughout the country. As well as finding a link between latitude and allergies to peanut and egg, the results showed that on average children in the south of the country are twice as likely to develop eczema as those in the north.
The report builds upon existing evidence that suggests exposure to the sun may play a role in rising levels of food allergy and eczema. Sunlight is important because it provides our body with the fuel to create vitamin D in the skin, and locations closer to the equator typically receive higher levels of sunshine. Australia is a particularly good place for this type of study as it spans nearly 3000 miles from north to south, with a large variation in climate, day length and sun strength - from Queensland in the north to Tasmania in the south.
Dr Nick Osborne, who led the research, believes these findings provide us with an important insight into the prevalence of food allergies and eczema, which appear to be on the increase. Dr Osborne also cautioned that exposure to sunlight can vary for a host of reasons beyond latitude, such as local climate variations and behaviours, and these factors will also need to be considered.
He said "This investigation has further underlined the association between food allergies, eczema and where you live. We're now hoping to study these effects at a much finer scale and examine which factors such as temperature, infectious disease or vitamin D are the main drivers of this relationship. As always, care has to be taken we are not exposed to too much sunlight, increasing the risk of skin cancer."
Vitamin D statement- European Menopause and Andropause Society January 2012
Osteoporosis is a common condition in postmenopausal women leading to bone fractures. However, there is now evidence that vitamin D deficiency is also associated with other medical conditions important in older women. These include cardiovascular disease, diabetes, cancer, infections and neurodegenerative disease. The major natural source of vitamin D is cutaneous synthesis through exposure to sunlight with a small amounts also coming from the diet in animal-based foods such as fatty fish, eggs and milk. Levels of vitamin D are lower in those with poor sun exposure and in the winter. Obesity, malabsorption syndromes and certain medications (e.g. anticonvulsants, antiretrovirals) can also lower vitamin D levels. Regular sunlight exposure (without sunscreens) for 15 minutes, 3-4 times a week, in the middle of the day in summer can generate healthy levels. Supplements of vitamin D are recommended for those women who cannot obtain the required quantity through sun exposure and diet. The recommended daily allowance is 600 IU/day increasing to 800IU/day for those aged 71 years and older.
Low vitamin D levels linked to depression
Low levels of vitamin D have been linked to depression, according to UT Southwestern Medical Center psychiatrists working with the Cooper Center Longitudinal Study. It is believed to be the largest such investigation ever undertaken.
Low levels of vitamin D already are associated with a cavalcade of health woes from cardiovascular diseases to neurological ailments. This new study – published in Mayo Clinic Proceedings – helps clarify a debate that erupted after smaller studies produced conflicting results about the relationship between vitamin D and depression. Major depressive disorder affects nearly one in 10 adults in the U.S.
"Our findings suggest that screening for vitamin D levels in depressed patients – and perhaps screening for depression in people with low vitamin D levels – might be useful," said Dr. E. Sherwood Brown, professor of psychiatry and senior author of the study, done in conjunction with The Cooper Institute in Dallas. "But we don't have enough information yet to recommend going out and taking supplements."
UT Southwestern researchers examined the results of almost 12,600 participants from late 2006 to late 2010. Dr. Brown and colleagues from The Cooper Institute found that higher vitamin D levels were associated with a significantly decreased risk of current depression, particularly among people with a prior history of depression. Low vitamin D levels were associated with depressive symptoms, particularly those with a history of depression, so primary care patients with a history of depression may be an important target for assessing vitamin D levels. The study did not address whether increasing vitamin D levels reduced depressive symptoms.
The scientists have not determined the exact relationship – whether low vitamin D contributes to symptoms of depression, whether depression itself contributes to lower vitamin D levels, or chemically how that happens. But vitamin D may affect neurotransmitters, inflammatory markers and other factors, which could help explain the relationship with depression, said Dr. Brown, who leads the psychoneuroendocrine research program at UT Southwestern.
Vitamin D levels are now commonly tested during routine physical exams, and they already are accepted as risk factors for a number of other medical problems: autoimmune diseases; heart and vascular disease; infectious diseases; osteoporosis; obesity; diabetes; certain cancers; and neurological disorders such as Alzheimer's and Parkinson's diseases, multiple sclerosis, and general cognitive decline.
Investigators used information gathered by the institute, which has 40 years of data on runners and other fit volunteers. UT Southwestern has a partnership with the institute, a preventive medicine research and educational nonprofit located at the Cooper Aerobics Center, to develop a joint scientific medical research program aimed at improving health and preventing a wide range of chronic diseases. The institute maintains one of the world's most extensive databases – known as the Cooper Center Longitudinal Study – that includes detailed information from more than 250,000 clinic visits that has been collected since Dr. Kenneth Cooper founded the institute and clinic in 1970.
Vitamin D deficiency = an increased risk of pelvic floor problems, including urinary incontinence
Vitamin D deficiency is higher among certain demographic segments, including women, the elderly, and the obese. All three groups also share an increased risk of pelvic floor problems, including urinary incontinence. Could there be a connection? Perhaps so, according to recent research.
A study published in Obstetrics & Gynecology compared vitamin D levels with incidence of various forms of pelvic floor disorder among 1,881 women, average age 48. Those with low levels of vitamin D (characterized as less than 30 nanograms per milliliter, or ng/ml) had a 170% increased risk of urinary incontinence, compared to those with higher blood levels.
Why might this be? As a hormone, vitamin D supports a myriad of bodily functions, including maintenance of muscle and bone. As a result, deficiency could undermine the muscular infrastructure of the pelvis needed for urinary control.
Vitamin D fights chronic digestive conditions
New research points to a potential role for UV light exposure and vitamin D levels in chronic digestive conditions; Crohn's disease, a serious inflammatory condition in the small intestine; and ulcerative colitis (UC), which similarly affects the colon.
In two separate studies presented at the American College of Gastroenterology's 76th Annual Scientific Meeting, (2011) a group of investigators from Massachusetts General Hospital probed the connection between geography, UV exposure and incidence of inflammatory bowel disease while another group from Weill Cornell Medical Center looked at different levels of supplementation with Vitamin D to determine impact on severity of Crohn's disease.
"Geographic Variations and Risk of Crohn's Disease and Ulcerative Colitis"
Results from two large prospective studies among large cohorts of nurses enrolled in the U.S. Nurses Health Study I and II revealed a significant north-south gradient in the association between latitude and incidence of Crohn's disease and ulcerative colitis in the United States. Such geographic variation has been reported in Europe, however comparable data in the United States are lacking, so this study advances understanding of the epidemiology of chronic inflammatory bowel disease, which affects as many as 1.4 million patients in the United States.
"This differential risk may be explained by differences in UV light exposure, vitamin D status, or pollution," explained Dr. Hamed Khalili, who, along Dr. Andrew Chan and colleagues at Massachusetts General Hospital, analyzed data that included a 4,209,454 person-year follow up in which they confirmed 284 cases of Crohn's disease and 332 cases of ulcerative colitis.
While the mean age of diagnosis among the women was 51 for Crohn's and 48 for UC, the investigators found that the women's geographic location at age 30 was strongly associated with incidence of disease. Based on geographic location at age 30, compared to women in northern latitudes, women in southern latitudes had an adjusted hazard ratio of 0.51 for Crohn's and 0.65 for UC suggesting that the risk of disease is 50% and 35% lower in the southern latitudes compared to northern latitudes for CD and UC, respectively. Further studies are warranted on underlying lifestyle and environmental factors that mediate this association, as well as their interaction with known genetic risk factors for CD and UC.
"High-dose Vitamin D3 Improves Clinical Activity in Crohn's Disease"
Results of an interim analysis of the first 15 patients in a study conducted at Weill-Cornell Medical and presented at the ACG Annual Scientific Meeting by Dustin Boothe, MD, sought to determine if high doses of Vitamin D3 supplementation in Vitamin D deficient patients with Crohn's disease leads to improved clinical outcomes.
Two groups of patients with Crohn's disease, who had baseline levels of Vitamin D that were low, were randomized to either low-dose (1,000 IU/day) or high-dose (10,000 IU/day) Vitamin D treatment and assessed at day 1, and after 8 weeks and 26 weeks of treatment. The investigators measured the patients's symptom severity using the Harvey-Bradshaw Index (HBI) an index of disease activity in Crohn's.
Results from the first 15 patients suggest that after 26 weeks of therapy, there were persistently significant differences in Vitamin D levels between the high-dose and low-dose groups, but importantly the low-dose group had no significant change in disease activity as measured by HBI at 26 weeks compared to baseline, whereas the high dose group did.
"Our interim analysis suggests that supplementation with 10,000 IU of Vitamin D3 may be an effective adjunctive therapy for ameliorating symptoms in Crohn's disease patients," commented Dr. Boothe on the presentation of these preliminary data.
Vitamin D Could Lower Risk of Developing Diabetes
Scientists at the Helmholtz Zentrum München have shown that people with a good vitamin D supply are at lower risk of developing Type 2 diabetes mellitus. The study, which was conducted in cooperation with the German Diabetes Center and the University of Ulm, will be published in the October edition of the scientific journal Diabetes Care.
New tests performed on participants of the KORA study have shown that people with a good supply of vitamin D have a lower risk of developing Type 2 diabetes mellitus, while individuals with lower concentrations of vitamin D in their blood have a higher risk. This effect could be attributable, amongst other things, to the anti-inflammatory effect of vitamin D. The result of the study, which was conducted at the Helmholtz Zentrum München in cooperation with Dr. Christian Herder of the German Diabetes Center in Düsseldorf and Dr. Wolfgang König, Professor of Medicine/Cardiology at the University of Ulm, could have direct consequences for the prevention of this common disease.
"Vitamin D deficiency is relatively widespread due to our modern way of life and the geographical latitude of Germany. In the winter months, in particular, people often do not receive adequate supplies of the vitamin because of the lack of sunlight," explains Dr. Barbara Thorand of the Institute for Epidemiology II at the Helmholtz Zentrum München. "If follow-up studies confirm our results, a targeted improvement in the supply of vitamin D to the general public could at the same time reduce the risk of developing diabetes." The human body can produce vitamin D itself if it has sufficient exposure to sunlight. The UVB radiation in natural daylight splits the precursor of vitamin D, 7-dehydrocholesterol, in the skin and forms provitamin D3. Further vitamin D synthesis occurs in the liver and kidneys. In addition, the supply can be improved by eating specific foods, such as oily fish, eggs and milk products, or by taking vitamin D supplements.
Pale people may need vitamin D supplements
Researchers at the University of Leeds, funded by Cancer Research UK, suggest that people with very pale skin may be unable to spend enough time in the sun to make the amount of vitamin D the body needs - while also avoiding sunburn.
The study, published in Cancer Causes and Control*, suggested that melanoma patients may need vitamin D supplements as well.
But researchers also noted that sunlight and supplements are not the only factors that can determine the level of vitamin D in a person's body.
Some inherited differences in the way people's bodies process vitamin D into the active form also have a strong effect on people's vitamin D levels.
The study defined the optimal amount of vitamin D required by the body as at least 60nmol/L. However at present there is no universally agreed standard definition of an optimal level of vitamin D.
Professor Julia Newton-Bishop, lead author of the study based in the Cancer Research UK Centre at the University of Leeds, said: "Fair-skinned individuals who burn easily are not able to make enough vitamin D from sunlight and so may need to take vitamin D supplements.
"This should be considered for fair-skinned people living in a mild climate like the UK and melanoma patients in particular."
Researchers took the vitamin D levels of around 1,200 people and found that around 730 people had a sub-optimal level. Those with fair-skin had significantly lower levels. Researchers chose 60nmol/L as the optimal vitamin D level in part because there is evidence that levels lower than this may be linked to greater risk of heart disease and poorer survival from breast cancer.
A consensus between health charities including Cancer Research UK says that levels below 25nmol/L are vitamin D deficient which means that these levels are associated with poor bone health. But some researchers consider that higher levels, around 60nmol/l, may be desirable for optimal health effects.
Sara Hiom, director of health information at Cancer Research UK, said: "We must be careful about raising the definition of deficiency or sufficiency to higher levels until we have more results from trials showing that maintaining such levels has clear health benefits and no health risks.
Vitamin D deficiency common in cancer patients
More than three-quarters of cancer patients have insufficient levels of vitamin D (25-hydroxy-vitamin D) and the lowest levels are associated with more advanced cancer, according to a study presented on October 2, 2011, at the 53rd Annual Meeting of the American Society for Radiation Oncology (ASTRO).
"Until recently, studies have not investigated whether vitamin D has an impact on the prognosis or course of cancer. Researchers are just starting to examine how vitamin D may impact specific features of cancer, such as the stage or extent of tumor spread, prognosis, recurrence or relapse of disease, and even sub-types of cancer," Thomas Churilla, lead author of the study and a medical student at the Commonwealth Medical College, Scranton, Pa., said.
Researchers sought to determine the vitamin D levels of patients at Northeast Radiation Oncology Center in Dunmore, Pa., a community oncology practice, and to see if vitamin D levels were related to any specific aspects of cancer. The study involved 160 patients with a median age of 64 years and a 1:1 ratio of men to women. The five most common primary diagnoses were breast, prostate, lung, thyroid and colorectal cancer. A total of 77 percent of patients had vitamin D concentrations either deficient (less than 20 ng/mL) or sub-optimal (20-30 ng/mL). The median serum vitamin D level was 23.5 ng/mL. Regardless of the age or sex of the patient, levels of vitamin D were below the median predicted for advanced stage disease in the patient group.
Patients who were found to be vitamin D deficient were administered replacement therapy, increasing serum D levels by an average of 14.9 ng/mL. Investigators will be analyzing if vitamin D supplementation had an impact on aspects of treatment or survival in the long-term.
"The benefits of vitamin D outside of improving bone health are controversial, yet there are various levels of evidence to support that vitamin D has a role in either the prevention or the prediction of outcome of cancer," Churilla said. "Further study is needed to continue to understand the relationship between vitamin D and cancer."
Vitamin D acts as a protective agent against the advance of colon cancer
A study conducted by VHIO researchers confirms that a lack of vitamin D increases the aggressiveness of colon cancer
The indication that vitamin D and its derivatives have a protective effect against various types of cancer is not new. In the field of colon cancer, numerous experimental and epidemiological studies show that vitamin D3 (or cholecalciferol) and some of its derivatives inhibit the growth of cancerous cells. Researchers at the Vall d'Hebron Institute of Oncology (VHIO), in collaboration with the Alberto Sols Institute of Biomedical Research (CSIC-UAB), have confirmed the pivotal role of vitamin D, specifically its receptor (VDR), in slowing down the action of a key protein in the carcinogenic transformation process of colon cancer cells. These results are being published in the journal PLoS One.
This protein, known as beta-catenin, which is normally found in intestinal epithelial cells where it facilitates their cohesion, builds up in large quantities in other areas of the cells when the tumour transformation begins. As a result of these changes, the protein is retained in the cell nucleus, where it facilitate the carcinogenic process, and this is the point at which vitamin D intervenes, or rather, the vitamin D receptor (VDR). "Our study has confirmed the pivotal role of the VDR in controlling the anomalous signal that sparks off the growth and uncontrolled proliferation of colon cells which, in the final instance, ends up causing a tumour to emerge", says Héctor Palmer, the coordinator of this study and head of the VHIO's Stem Cells and Cancer laboratory. He continues, "The stimulation of this receptor suppresses the action of the beta-catenin protein, intercepting the series of events that change the intestinal cell into a malignant tumour cell".
The study was conducted on mice and human colon cancer cells. The mice were used as a model to replicate the initial phases of colon cancer. "These findings show that mice of this kind, which also lack the VDR and hence do not respond to vitamin D, present larger and more aggressive tumours than mice with the VDR", explains Dr. Palmer, and concludes: "The number of tumours is not influenced by the absence of VDR, which would indicate that this factor does not protect against the appearance of the tumour but does intervene in its growth phase, reducing its aggressiveness".
The researchers then analysed the effect of the VDR on human colon cancer cell cultures and observed that the concentration of the altered protein, beta-catenin, increased in cells without the VDR. These findings were repeated in the three types of colon cancer cells studied, and confirmed the results observed in the mice.
In two-thirds of advanced colon cancer tumours there was a lack of VDR in the cancer cells, and this circumstance leads us to believe that this loss may contribute to speeding up the growth of the tumour. The findings of this study confirm this supposition.
Vitamin D: essential in the initial phases of colon cancer
In light of these findings, chronic vitamin D deficiency represents a risk factor in the development of more aggressive colon tumours. Patients in the initial stages of colon cancer, the time when the VDR still has a substantial presence in the cells, could benefit from being treated with vitamin D3. However, this would not be useful in the advanced stages of the disease when the presence of the VDR is very much reduced.
The study data support the development of anti-tumour medicines based on the structure of vitamin D, although their use in patients will require further research in the next few years.
The body not only obtains vitamin D from food, especially milk and fish oils, but also manufactures it from exposure to sunlight. Prolonged exposure is not necessary; just 10 minutes in the sun every day when it is not at its peak is sufficient to stimulate its production. During the summer, when we are more likely to sunbathe, it is important to use the appropriate protective measures against sunburn to avoid future sun damage. Use high-factor solar protection products and do not expose the skin to the sun in the middle of the day to protect against skin cancers.
Vitamin D relieves joint, muscle pain for breast cancer patients
High-dose vitamin D relieves joint and muscle pain for many breast cancer patients taking estrogen-lowering drugs, according to a new study from Washington University School of Medicine in St. Louis.
The drugs, known as aromatase inhibitors, are commonly prescribed to shrink breast tumors fueled by the hormone estrogen and help prevent cancer recurrence. They are less toxic than chemotherapy, but for many patients, the drugs may cause severe musculoskeletal discomfort, including pain and stiffness in the hands, wrists, knees, hips, lower back, shoulders and feet.
“About half of patients can experience these symptoms,” says Antonella L. Rastelli, MD, assistant professor of medicine and first author of the study published online in the journal Breast Cancer Research and Treatment. “We don’t know exactly why the pain occurs, but it can be very debilitating — to the point that patients decide to stop taking aromatase inhibitors.”
Because the drugs reduce cancer recurrence, finding a way to help patients stay on them is important for long-term, relapse-free survival, according to Rastelli. Aromatase inhibitors are prescribed to post-menopausal women for at least five years and often longer after a breast cancer diagnosis. There is some evidence that patients who experience the drugs’ side effects are less likely to see their cancer return, providing even more incentive to help these patients continue taking them.
It was Rastelli’s colleague, Marie E. Taylor, MD, assistant professor of radiation oncology, who first noticed that patients on aromatase inhibitors who experienced this pain found some relief from high doses of vitamin D.
So Rastelli’s group recruited 60 patients who reported pain and discomfort associated with anastrozole, one of three FDA-approved aromatase inhibitors. The patients they studied also had low vitamin D levels. Half the group was randomly assigned to receive the recommended daily dose of vitamin D (400 international units) plus a 50,000-unit vitamin D capsule once a week. The other half received the daily dose of 400 units of vitamin D plus a weekly placebo. All subjects received 1,000 milligrams of calcium daily throughout the study.
Patients in the study reported any pain they experienced through three different questionnaires. They were asked to quantify their pain intensity, as well as report how much the pain altered their mood, affected their work and interfered with relationships and daily activities. The results show that patients receiving high-dose vitamin D every week reported significantly less musculoskeletal pain and also were less likely to experience pain that interfered with daily living.
“High-dose vitamin D seems to be really effective in reducing the musculoskeletal pain caused by aromatase inhibitors,” Rastelli says. “Patients who get the vitamin D weekly feel better because their pain is reduced and sometimes goes away completely. This makes the drugs much more tolerable. Millions of women worldwide take aromatase inhibitor therapy, and we may have another ‘tool’ to help them remain on it longer.”
Like anastrozole used in this study, the other two FDA-approved aromatase inhibitors, letrozole and exemestane, also cause musculoskeletal pain. Given the similar side effects, Rastelli says patients on these drugs may also benefit from high-dose vitamin D.
The vitamin used in this study is a plant-derived type called vitamin D2. Rastelli says it achieves the best results when given weekly because the body metabolizes it within seven to 10 days. Rastelli and her colleagues did not use high-dose vitamin D3, which remains in the body longer.
“This was a very carefully conducted study, and the placebo control makes the findings quite compelling,” says Matthew J. Ellis, MD, PhD, the study’s senior author and director of the Breast Cancer Program at the Alvin J. Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of Medicine in St. Louis. “We should follow up these findings further to determine the most efficacious and safe approach to vitamin D supplementation in our breast cancer patients.”
Since vitamin D helps the body absorb calcium, too much of it can cause high levels of calcium in the urine, which may increase the risk of kidney stones. Such possible side effects emphasize the importance of tracking patients’ urine calcium levels while taking high-dose vitamin D.
“It’s important to monitor the patients, but overall it appears to be very safe,” Rastelli says. “Because vitamin D2 is eliminated from the body so quickly, it’s very hard to overdose.”
In addition to relieving pain, the group wanted to examine whether vitamin D could protect against the bone loss often seen in patients taking aromatase inhibitors. The researchers measured each patient’s bone density at the beginning of the study and again after six months.
Perhaps because of its role in calcium absorption, high-dose vitamin D did appear to help maintain bone density at the neck of the femur, the top of the thighbone near the hip joint. Although the result did not reach statistical significance, Rastelli calls the result promising and worth further studies.
“It’s great that we have something as simple as vitamin D to help patients alleviate some of this pain,” Rastelli says. “It’s not toxic — it doesn’t cause major side effects. And if it is actually protecting against bone loss, that’s even better.”
Calcium Plus Vitamin D May Reduce Melanoma Risks
A combination of calcium and vitamin D may cut the chance of melanoma in half for some women at high risk of developing this life-threatening skin cancer, according to a new study by Stanford University School of Medicine researchers.
Using existing data from a large clinical trial, the study zeroed in on women with a history of non-melanoma skin cancer, as people with this generally non-fatal disease are more likely to develop the more lethal illness -- melanoma. The researchers found that women who once had non-melanoma and took the calcium-vitamin D combination developed 57 percent fewer melanomas than women with similar histories who were not given the supplements. Non-melanoma skin cancers, such as basal cell or squamous cell cancers, are the most common forms of skin cancer.
"In preventive medicine, we want to target people most at risk for the disease," said dermatologist Jean Tang, MD, PhD, lead author of the study. "If you previously had a non-melanoma skin cancer, calcium plus vitamin D might reduce your risk of the more deadly melanoma."
Tang added a note of caution. The study found that a daily dose of 1,000 mg calcium plus 400 IU of vitamin D doesn't provide skin cancer protection for everybody. Women without a history of non-melanoma skin cancer who took the supplements did not see any reduction of risk compared with their placebo-group counterparts, according to the research.
The study was published online on June 27, 2011 in the Journal of Clinical Oncology.
Vitamin D is well-known for its role in bone growth, but it also affects non-skeletal cells. In many parts of the body, including the skin, vitamin D controls how quickly cells replicate, a process that often goes awry in cancer. Reports from various institutions have suggested that vitamin D is associated with lower risks of colon, breast, prostate and other cancers. Nonetheless, the Institute of Medicine published a report last November saying that more research was needed on vitamin D and calcium, as the evidence was insufficient to prove their having a benefit for conditions other than bone health.
This study is the second to look at the effect of vitamin D supplementation on cancer risk with a randomized, controlled trial.
Tang and colleagues analyzed data from the Women's Health Initiative, a study that followed 36,000 women ages 50 to 79 for an average of seven years. Half of the women took the daily dose of calcium and vitamin D as part of the experiment; the other half took a placebo pill. The WHI calcium plus vitamin D trial was designed to look at the effects of the supplement on hip fractures and colorectal cancers, but its researchers collected data on many other health issues, including other cancers.
Tang and colleagues took advantage of the large and long-term data set provided by the WHI trial to explore whether vitamin D has a protective effect against skin cancer. "Our results include the first positive cancer-reducing effect seen from the calcium plus vitamin D trial," said Teresa Fu, MD, a co-author of the study and a recent graduate of the School of Medicine.
The lack of protective effect in women without a history of non-melanoma skin cancer may be due to the amount of vitamin D given to the patients in the WHI trial. "The patients in the Women's Health Initiative were given vitamin D at a very low dose, based on today's knowledge -- only 400 IU per day," said David Feldman, MD, professor emeritus of endocrinology and a co-author of the study. Furthermore, patients in the placebo group were allowed to take as much vitamin D as patients that were provided the calcium and vitamin D supplements, so the experimental difference between the two groups was small. In light of that small difference, "it's somewhat surprising that there was an effect on melanoma risk, and I think many potential benefits of vitamin D may not have been detected," said Feldman.
Because men were not included in the trial, the researchers cannot be certain whether the protective effect of the supplements would also apply to men with a history of non-melanoma skin cancer. Nonetheless, a 2010 study by Tang demonstrated that elderly men with higher blood levels of vitamin D have fewer non-melanoma skin cancers.
Even in a large study like the WHI, the low frequency of melanomas means that the absolute number of cancers was small. Out of the 36,000 participants, only 176 cases of melanoma were reported. "That just highlights how large a trial needs to be to capture cancer as relatively rare as melanoma," said Marcia Stefanick, PhD, the Stanford WHI principal investigator and senior author of this study.
"These results spur us to do more studies," said Tang. She is planning multiple lines of research to examine the potential relationship between vitamin D and cancer prevention, including a study that will compare blood levels of vitamin D with melanoma outcomes. Another line of research will examine the effect of larger doses of vitamin D on the behavior
Vitamin D can help elderly women survive
Giving vitamin D3 (cholecalciferol) to predominantly elderly women, mainly in institutional care, seems to increase survival. These women are likely to be vitamin D deficient with a significant risk of falls and fractures. This is the key conclusion in a systematic review published in the latest edition of The Cochrane Library.
Up until now there has been no clear view on whether there is a real benefit of taking vitamin D. "A Cochrane meta-analysis published only a couple of years ago found that there was some evidence for benefit, but it could not find an effect on mortality. We were, however, aware that more trials had been published and wanted to assess the effects of vitamin D when you added all the data together," said Dr Goran Bjelakovic, who works at Department of Internal Medicine - Gastroenterology and Hepatology, at the University of Nis, in Serbia and at The Cochrane Hepato-Biliary Group at The Copenhagen Trial Unit in Copenhagen, Denmark.
The eight-strong international team of researchers identified 50 randomised trials that together had 94,148 participants. They had a mean age of 74 years, and 79% were women. "Our analyses suggest that vitamin D3 reduces mortality by about 6%. This means that you need to give about 200 people vitamin D3 for around two years to save one additional life," says Bjelakovic.
There were no significant benefits of taking other forms of vitamin D such as vitamin D2, and the active forms of the vitamin, alfacalcidol or calcitriol. However, the researchers point out that they could only find much less data relating to these types of vitamin D and so these conclusions should be taken with caution. "We need to have more randomised trials that look specifically to see whether these forms of vitamin D do or don't have benefits," says Bjelakovic. His team did conclude that alfacalcidol and calcitriol significantly increased the risk of hypercalcaemia, and vitamin D3 combined with calcium significantly increased the risk of kidney stones.
There have been reports and comments that taking vitamin D can reduce the risk of getting cancer, but this work showed no evidence that vitamin D reduced cancer-related mortality.
"Previous reviews of preventive trials of vitamin D have not included as much information and have not examined the separate influence of different forms of vitamin D on mortality. By taking data from a larger number of trials we have been able to shed much more light on this important issue," says Bjelakovic.
Vitamin D Boosts Immune Response
Laboratory-grown gingival cells treated with vitamin D boosted their production of an endogenous antibiotic, and killed more bacteria than untreated cells, according to a paper in the June 2011 issue of the journal Infection and Immunity. The research suggests that vitamin D can help protect the gums from bacterial infections that lead to gingivitis and periodontitis. Periodontitis affects up to 50 percent of the US population, is a major cause of tooth loss, and can also contribute to heart disease. Most Americans are deficient in vitamin D.
His interest piqued by another laboratory's discovery that vitamin D could stimulate white blood cells to produce natural proteins that have antibiotic activity, Gill Diamond of the UMDNJ -- New Jersey Dental School, Newark, showed that vitamin D could stimulate lung cells to produce LL-37, a natural antibiotic protein, and kill more bacteria. That suggested that , vitamin D might help cystic fibrosis patients. Next, in the new research, he showed that vitamin D has the same effct on gingival cells.
Then, Diamond found that vitamin D also stimulates gingival cells to produce another protein, called TREM-1, which had not been well-studied, but which was thought to be made by white blood cells. He found that it boosts production of pro-inflammatory cytokines.
The new research also showed that vitamin D coordinates expression of a number of genes not previously considered to be part of the vitamin D pathway. Those genes may be involved in additional infection-fighting pathways. A more comprehensive understanding of how vitamin D carries out this regulation at the molecular level -- something Diamond hopes to investigate -- will enable targeted therapies using vitamin D, he says.
Interestingly, Diamond also found that lung and gum cells appear to have the ability to activate inactive forms of vitamin D, says Diamond. "This means that we may even be able to use vitamin D therapy topically, if that proves true."
Vitamin D has become a hot area of research in recent years. In addition to infectious diseases, studies suggest that it has protective effects against autoimmune diseases, and certain cancers.
Diamond says that after he began conducting research on vitamin D, he began taking it as a supplement. Since then, "I have had only one cold in four years, and that one lasted only three days," he says. "Other people I've met who have done the same have seen similar results. We are trying to figure out how it's working, and what other infectious diseases can be mitigated by it."
High levels of vitamin D needed for bone density drugs to work
To fully optimize a drug therapy for osteoporosis and low bone mineral density (BMD), patients should maintain vitamin D levels above the limits recently recommended by the Institute of Medicine (IOM), according to a new study by researchers from Hospital for Special Surgery in New York. The study was presented at the Endocrine Society's Annual Meeting in Boston, June 4-7, 2011.
The study demonstrated that maintaining a circulating vitamin D level above 33 ng/ml is associated with a seven-fold greater likelihood of having a more favorable outcome with bisphosphonate therapy. Last November, the IOM issued recommendations that 25-Hydroxy vitamin D levels of 20-30 ng/ml were adequate for normal, healthy people.
"You are seven times more likely to respond to bisphosphonates if your 25-Hydroxy vitamin D level is 33 ng/ml and above. If you want to see a particular outcome from this treatment, then maybe 20 to 30 is not appropriate," said Richard Bockman, M.D., Ph.D., chief of the Endocrine Service at Hospital for Special Surgery, who directed the study. "When you see a seven times greater effect, that is pretty impressive."
More than 20 million people take bisphosphonates to preserve and improve skeletal health, and reduce the risk of fractures that can be caused by low BMD and osteoporosis. These drugs, however, do not work well in some patients. Because vitamin D is important to bone health, the researchers investigated whether they could identify levels of vitamin D that are associated with improved outcomes in patients taking bisphosphonates.
They conducted a retrospective chart review of patients seen in an osteoporosis practice of Hospital for Special Surgery. They identified subjects who were female, postmenopausal, had been taking one of four FDA-approved bisphosphonate drugs for at least 18 months, and had undergone at least two BMD scans separated by 18 to 60 months. The four drugs are alendronate, residronate, ibandronate and zolendronate. Patients were not included if they were nonadherent to bisphosphonate therapy, were chronic steroid users, or had metabolic bone disease or chronic kidney disease.
The researchers collected data on age, body mass index, type of bisphosphonate taken, treatment duration, concurrent calcium supplementation, fracture prior to and during bisphosphonate therapy, BMD and T-score at four sites—lumbar spine, femoral neck, trochanter, and total hip—from the two most recent bone scans. "The way the data are expressed for a bone density is how many standard deviations are you away from the normal," explained Dr. Bockman. "One standard deviation from the normal is a T score of one. Two standard deviations is a T score of two. Below the normal, it is a minus two and above the normal is a plus two. If your bone density is more than 2.5 standard deviations below the normal, that defines a low bone mass that is considered to be osteoporosis." The researchers also collected data on circulating levels of vitamin D, obtained with and between the two most recent bone scans.
Patients were deemed nonresponders if they had more than a 3 percent decrease in BMD between the initial and follow-up bone scans, a low-trauma fracture or a T-score less than -3.0 despite at least 24 months of bisphosphonate therapy.
The study included 160 patients, of whom 89 were responders, and 71 were nonresponders, with 42 having decreased BMD, 17 sustaining a fracture, and 12 having a persistent low T-score. The investigators found that only 16.8 percent of responders whereas 54.9 percent of nonresponders had vitamin D levels less than 33 ng/ml. Patients with an average circulating vitamin D level of 33 ng/ml and above had a seven-fold greater likelihood of having a favorable response to bisphosphonates. "We selected 33 as the cutoff and subsequently showed that it was the right choice, with more being better," Dr. Bockman said. Nonresponse rates were higher in patients who had low levels of vitamin D: < 20 ng/ml (83.3%), 20-30 ng/ml (77.8%), 30-40 ng/ml (42.3%), and >40 ng/ml (24.6%).
"If you look at the medical literature, researchers talk perhaps about a 20 percent increase in response rate, occasionally a doubling, but when you see a sevenfold improvement in outcome, you have to be impressed that it is probably important," said Dr. Bockman, who is also professor of Medicine in the Endocrine Division of Weill Cornell Medical College.
Before this study, researchers had not formally studied the relationship between vitamin D levels and the effectiveness of bisphosphonates. "There has been a lot of controversy over the correct vitamin D level for people to have," Dr. Bockman said. "Vitamin D status should be optimized to improve outcomes in patients taking bisphosphonates."
Dr. Bockman pointed out that three associations—the American Geriatric Society, Endocrine Society, and the American College of Rheumatology—are coming out with or have guidelines that recommend vitamin D levels higher than the IOM recommended levels for healthy people.
Vitamin D deficiency associated with increased mortality
A new study published in the journal Respirology reveals that adult patients admitted to the hospital with pneumonia are more likely to die if they have Vitamin D deficiency.
Vitamin D is known to be involved in the innate immune response to infection.
The team of researchers at Waikato Hospital and the Universities of Waikato and Otago, measured vitamin D in the blood samples of 112 adult patients admitted with community acquired pneumonia during the winter at the only acute-care hospital in Hamilton, New Zealand.
The researchers found that Vitamin D deficiency was associated with higher mortality within the first 30 days after hospital admission for pneumonia. The association between vitamin D deficiency was not explained by patient age, sex, comorbidities, the severity of the systemic inflammatory response, or other known prognostic factors.
The authors conclude that "improved understanding of Vitamin D and its role in immunity may lead to better ways to prevent and/or treat pneumonia. We now need to investigate whether Vitamin D supplements could be a useful addition to pneumonia treatment and whether using supplements could help to prevent or reduce the severity of pneumonia among high-risk populations."
Vitamin D may help reduce heart risk in African-Americans
Supplementation of 60,000 IU monthly improves vascular function
In recent years supplementation with Vitamin D has been shown to reduce the risk of cardiovascular disease (CVD) in people who are deficient in the vitamin. Now new research from the Georgia Prevention Institute at Georgia Health Sciences University in Augusta indicates that supplementation with the "sunshine vitamin" may be particularly beneficial for overweight African-American adults, a population at increased risk for both CVD and Vitamin D deficiency.
According to Ryan A. Harris, PhD, assistant professor, the Georgia team's research suggests that Vitamin D supplementation cut the cardiovascular risk by improving the health and function of vascular endothelial cells, cells that line the inside of blood vessels. He will discuss the team's findings at the Experimental Biology 2011 meeting (EB 2011), being held April 9-13, 2011 at the Walter E. Washington Convention Center in Washington, DC. The presentation is entitled "Vitamin D Improves Flow-Mediated Dilation in African American Adults."
A Population at Risk
African-Americans as a group have multiple risk factors for CVD. They are more likely than people of other races to develop type 2 diabetes, a known contributor to CVD, and when they develop high blood pressure it tends to be more severe than that of other groups. African-Americans also have a greater risk of developing Vitamin D deficiency: The pigmentation in their skin inhibits their skin cells' ability to produce Vitamin D in response to exposure to sunlight.
In the study, 45 overweight African-American adults who were separated into two groups. (Overweight participants were chosen because carrying extra weight has been linked to inflammation in blood vessels, another risk for CVD.) One group, the treatment group, received 60,000 IU of Vitamin D in a single dose every 4 weeks for 16 weeks. The second group, the placebo group, received dummy pills. Although 60,000 IU seems like a high dose, Vitamin D has a half life of approximately 3 weeks, which means that half the dose is still in the body 3 weeks after it is taken. Given the time it takes the body to clear Vitamin D, a dose of 60,000 IU equals about 2,000 IU a day.
"We could have used daily dosing, but we knew compliance would be better with monthly dosing. One dose a month is easier than taking two pills a day," says Dr. Harris. He notes that participants reported no side effects.
At the beginning of the study, the researchers used an inflatable cuff to increase blood flow in the brachial arteries of the participants' arms, then used ultrasound to measure the arteries flow-mediated dilation. Flow-mediated dilation occurs when blood vessels dilate, or open up, in response to increased blood flow, which allows the blood to flow more freely. Vascular endothelial cells play a role in blood vessel dilation; endothelial cell dysfunction is considered to be the first sign of atherosclerosis, or "hardening of the arteries." When there is endothelial dysfunction, the blood vessels do not dilate as much and the heart has to pump harder to push blood through the vessels.
After 16 weeks, the researchers measured the participants' flow-mediated dilation again and found that flow-mediated dilation had improved in the treatment group, but not in the placebo group.
"This points to a beneficial effect of Vitamin D supplementation on endothelial cell function," says Dr. Harris. He adds that this is good news for African-Americans, given their risks for CVD. "If you're deficient in Vitamin D and you take supplements, you have a good probability of increasing endothelial function and therefore decreasing the risk of cardiovascular disease."
Exactly how Vitamin D works on the endothelial cells is the "million-dollar question" Dr. Harris says. "Vitamin D interacts with a lot of different systems in the body. It may decrease inflammation, which is better for endothelial function."
Vitamin D Levels Linked With Health of Blood Vessels
A lack of vitamin D, even in generally healthy people, is linked with stiffer arteries and an inability of blood vessels to relax, research from the Emory/Georgia Tech Predictive Health Institute has found.
The results add to evidence that lack of vitamin D can lead to impaired vascular health, contributing to high blood pressure and the risk of cardiovascular disease. Study participants who increased their vitamin D levels were able to improve vascular health and lower their blood pressure.
The data was presented by Ibhar Al Mheid, MD, a cardiovascular researcher at Emory University School of Medicine, at the annual American College of Cardiology meeting in New Orleans. Al Mheid is one of five finalists for the ACC's Young Investigators Award competition in physiology, pharmacology and pathology. He is working with Arshed Quyyumi, MD, professor of medicine and director of the Emory Cardiovascular Research Institute.
The 554 participants in the study were Emory or Georgia Tech employees -average age 47 and generally healthy -- who are taking part in the Center for Health Discovery and Well Being, part of the Emory/Georgia Tech Predictive Health Institute.
The average level of 25-hydroxyvitamin D (a stable form of the vitamin reflecting diet as well as production in the skin) in participants' blood was 31.8 nanograms per milliliter. In this group, 14 percent had 25-hydroxyvitamin D levels considered deficient, or less than 20 nanograms per milliliter, and 33 percent had levels considered insufficient, less than 30 nanograms per milliliter.
The researchers monitored the ability of participants' blood vessels to relax by inflating and then removing a blood pressure cuff on their arms. To allow blood to flow back into the arm, blood vessels must relax and enlarge -- a change that can be measured by ultrasound. The researchers also made other measurements of smaller blood vessels and examined the resistance to blood flow imposed by the arteries.
Even after controlling for factors such as age, weight and cholesterol, people with lower vitamin D levels still had stiffer arteries and impaired vascular function, Al Mheid says.
"We found that people with vitamin D deficiency had vascular dysfunction comparable to those with diabetes or hypertension," he says.
Throughout the body, a layer of endothelial cells lines the blood vessels, controlling whether the blood vessels constrict or relax and helping to prevent clots that lead to strokes and heart attacks.
"There is already a lot known about how vitamin D could be acting here," Al Mheid says. "It could be strengthening endothelial cells and the muscles surrounding the blood vessels. It could also be reducing the level of angiotensin, a hormone that drives increased blood pressure, or regulating inflammation."
Most Americans generally get the majority of their vitamin D from exposure to sunlight or from dietary supplements; fortified foods such as milk or cereals are a minor source. A few foods, such as oily fish, naturally contain substantial amounts of vitamin D.
Participants whose vitamin D levels increased over the next six months, either from dietary supplements or ample sun exposure, tended to improve their measures of vascular health and had lower blood pressure. Forty-two study participants with vitamin D insufficiency whose levels later went back to normal had an average drop in blood pressure of 4.6 millimeters mercury.
Vitamin D Fights Lung Cancer
Recent research suggests vitamin D may be able to stop or prevent cancer. Now, a new study finds an enzyme that plays a role in metabolizing vitamin D can predict lung cancer survival.
The study, from researchers at the University of Michigan Comprehensive Cancer Center, suggests that this enzyme stops the anti-cancer effects of vitamin D.
Levels of the enzyme, called CYP24A1, were elevated as much as 50 times in lung adenocarcinoma compared with normal lung tissue. The higher the level of CYP24A1, the more likely tumors were to be aggressive. About a third of lung cancer patients had high levels of the enzyme. After five years, those patients had nearly half the survival rate as patients with low levels of the enzyme.
Researchers then linked this to how CYP24A1 interacts with calcitriol, the active form of vitamin D. CYP24A1 breaks down calcitriol, which has a normal and crucial role when kept in check. But when levels of CYP24A1 climb, the enzyme begins to hinder the positive anti-cancer effects of vitamin D.
Results of the study appear in Clinical Cancer Research.
Previous studies have linked low levels of vitamin D to a higher incidence of cancer and worse survival. Researchers are looking at using vitamin D to help prevent lung cancer from returning and spreading after surgery. This new study suggests the possibility of using CYP24A1 levels to personalize this approach to those likely to benefit most.
"Half of lung cancers will recur after surgery, so it's important to find a way to prevent or delay this recurrence. A natural compound like vitamin D is attractive because it has few side effects, but it's even better if we can determine exactly who would benefit from receiving vitamin D," says study author Nithya Ramnath, M.D., associate professor of internal medicine at the U-M Medical School.
Researchers also are working to identify drugs that block CYP24A1. Blocking the enzyme would reinstate the positive anti-cancer effects of vitamin D, suggesting that this inhibitor could potentially be combined with vitamin D treatments.
Higher vitamin D intake needed to reduce cancer risk
Researchers at the University of California, San Diego School of Medicine and Creighton University School of Medicine in Omaha have reported that markedly higher intake of vitamin D is needed to reach blood levels that can prevent or markedly cut the incidence of breast cancer and several other major diseases than had been originally thought. The findings are published February 21, 2011 in the journal Anticancer Research.
While these levels are higher than traditional intakes, they are largely in a range deemed safe for daily use in a December 2010 report from the National Academy of Sciences Institute of Medicine.
"We found that daily intakes of vitamin D by adults in the range of 4000-8000 IU are needed to maintain blood levels of vitamin D metabolites in the range needed to reduce by about half the risk of several diseases - breast cancer, colon cancer, multiple sclerosis, and type 1 diabetes," said Cedric Garland, DrPH, professor of family and preventive medicine at UC San Diego Moores Cancer Center. "I was surprised to find that the intakes required to maintain vitamin D status for disease prevention were so high – much higher than the minimal intake of vitamin D of 400 IU/day that was needed to defeat rickets in the 20th century."
"I was not surprised by this" said Robert P. Heaney, MD, of Creighton University, a distinguished biomedical scientist who has studied vitamin D need for several decades. "This result was what our dose-response studies predicted, but it took a study such as this, of people leading their everyday lives, to confirm it."
The study reports on a survey of several thousand volunteers who were taking vitamin D supplements in the dosage range from 1000 to 10,000 IU/day. Blood studies were conducted to determine the level of 25-vitamin D – the form in which almost all vitamin D circulates in the blood.
"Most scientists who are actively working with vitamin D now believe that 40 to 60 ng/ml is the appropriate target concentration of 25-vitamin D in the blood for preventing the major vitamin D-deficiency related diseases, and have joined in a letter on this topic," said Garland. "Unfortunately, according a recent National Health and Nutrition Examination Survey, only 10 percent of the US population has levels in this range, mainly people who work outdoors."
Interest in larger doses was spurred in December of last year, when a National Academy of Sciences Institute of Medicine committee identified 4000 IU/day of vitamin D as safe for every day use by adults and children nine years and older, with intakes in the range of 1000-3000 IU/day for infants and children through age eight years old.
While the IOM committee states that 4000 IU/day is a safe dosage, the recommended minimum daily intake is only 600 IU/day.
"Now that the results of this study are in, it will become common for almost every adult to take 4000 IU/day," Garland said. "This is comfortably under the 10,000 IU/day that the IOM Committee Report considers as the lower limit of risk, and the benefits are substantial." He added that people who may have contraindications should discuss their vitamin D needs with their family doctor.
"Now is the time for virtually everyone to take more vitamin D to help prevent some major types of cancer, several other serious illnesses, and fractures," said Heaney.
Sun exposure, vitamin D may lower risk of multiple sclerosis
People who spend more time in the sun and those with higher vitamin D levels may be less likely to develop multiple sclerosis (MS), according to a study published in the February 8, 2011, print issue of Neurology®, the medical journal of the American Academy of Neurology. MS is a chronic disease of the brain and spinal cord, usually with recurrent flare-ups of symptoms. It is often preceded by a first episode (or event) of similar symptoms lasting days to weeks.
"Previous studies have found similar results, but this is the first study to look at people who have just had the first symptoms of MS and haven't even been diagnosed with the disease yet," said study author Robyn Lucas, PhD, of Australian National University in Canberra. "Other studies have looked at people who already have MS—then it's hard to know whether having the disease led them to change their habits in the sun or in their diet."
The multi-site study involved 216 people age 18 to 59 who had a first event with symptoms of the type seen in MS. Those people were matched with 395 people with no symptoms of possible MS who were of similar ages, of the same sex and from the same regions of Australia.
The participants reported how much sun they were exposed to during different periods of their lives, and researchers also measured the amount of skin damage participants had from sun exposure and the amount of melanin in their skin. Vitamin D levels (from sun exposure, diet and supplement use) were measured by blood tests.
The risk of having a first event, diagnosed by a doctor, ranged from approximately two to nine new cases for every 100,000 people per year in this study. The reported UV light exposure of participants ranged from about 500 to over 6,000 kilojoules per meter squared. The researchers found that the risk of having a diagnosed first event decreased by 30 percent for each UV increase of 1,000 kilojoules. They also found that people with most evidence of skin damage from sun exposure were 60 percent less likely to develop a first event than the people with the least damage. People with the highest levels of vitamin D also were less likely to have a diagnosed first event than people with the lowest levels.
Studies have shown that MS is more common in latitudes further away from the equator, and this has been confirmed in Australia.
"Added together, the differences in sun exposure, vitamin D levels and skin type accounted for a 32-percent increase in a diagnosed first event from the low to the high latitude regions of Australia," Lucas said.
Lucas noted that the effects of sun exposure and vitamin D acted independently of each other on the risk of first event. "Further research should evaluate both sun exposure and vitamin D for the prevention of MS," Lucas said.
Lucas also stated that people should continue to limit their sun exposure due to skin cancer risks. She also noted that the risks of tanning beds far outweigh any possible protective effect against MS. Exposure to the sun has not been shown to benefit people who already have MS.
Vitamin D deficiencies may = autoimmune lung disease
A new study shows that vitamin D deficiency could be linked to the development and severity of certain autoimmune lung diseases.
These findings are being reported in the Jan. 4, 2011 edition of the journal Chest.
Brent Kinder, MD, UC Health pulmonologist, director of the Interstitial Lung Disease Center at the University of Cincinnati and lead investigator on the study, says vitamin D deficiencies have been found to affect the development of other autoimmune diseases, like lupus and type 1 diabetes.
"We wanted to see if lack of sufficient vitamin D would also be seen in patients who are diagnosed with an autoimmune interstitial lung disease (ILD) and whether it was associated with reduced lung function," he says.
Some ILD patients first discover they have an undifferentiated connective tissue disease, a chronic inflammatory autoimmune disease that affects multiple organ systems but is not developed enough for physicians to easily recognize and categorize.
Autoimmune diseases occur when the body produces abnormal cells that turn on the body and attack major organs and tissues. Connective tissue diseases include lupus, scleroderma, polymyositis, vasculitis, rheumatoid arthritis and Sjogren's syndrome.
"ILD is a group of diseases that mainly affect the tissues of the lungs instead of the airways, like asthma and emphysema do," says Kinder. "It causes scarring of the lungs, is more difficult to diagnosis and treat than other kinds of lung diseases and is often fatal.
"Since vitamin D deficiency has implications for other manifestations of autoimmune illnesses, we wanted to see it had an effect on the lungs of this patient population."
Researchers evaluated 118 patients from the UC ILD Center database—67 with connective tissue disease-related ILD and 51 with other causes of lung fibrosis—for serum 25-hydroxyvitamin D levels, which indicate levels of vitamin D in the body. Then, they evaluated associations between these serum levels and the patients' conditions.
Overall, those with connective tissue disease-related ILD were more likely to have vitamin D deficiency—52 percent versus 20 percent—and insufficiency—79 percent versus 31 percent—than other forms of ILD.
Among this same group of patients, reduced serum 25-hydroxyvitamin D levels were strongly associated with reduced lung function.
"These findings suggest that there is a high prevalence of vitamin D deficiency in patients with ILD, particularly those with connective tissue disease," Kinder says. "Therefore, vitamin D may have a role in the development of connective tissue disease-related ILD and patients' worsening lung function.
"One of the next steps is to see if supplementation will improve lung function for these patients."
He adds that if these findings are confirmed and vitamin D supplementation is shown to be effective in clinical trials, this may also provide a more natural, inexpensive treatment for the illness.
"Vitamin D is known to be a critical dietary factor for bone and skin health," he says. "Now, we're learning that it could potentially be modified as a treatment to improve ILD as opposed to other, more toxic therapies."
Vitamin D Helps Prevent Falls in Seniors
A systematic review of over 50 clinical trials finds that exercise and Vitamin D supplements are the best ways to reduce the risk of falling in people aged 65 and over. The review is published in the December 21, 2011 issue of Annals of Internal Medicine and was commissioned by the US Preventive Services Task Force. A researcher at the Drexel University School of Public Health worked with colleagues at the Kaiser Permanente Center for Health Research, which is part of the Oregon Evidenced-based Practice Center, to conduct the study.
For the review of Vitamin D supplementation researchers evaluated nine clinical trials involving nearly 6,000 participants who received daily oral doses of Vitamin D with or without calcium. The dosage ranged from 10 to 1,000 IU’s per day, in one trial participants received a larger single intramuscular injection of 600,000 IU’s of Vitamin D. The trials lasted from eight weeks to three years. Follow up periods ranged from six to 36 months. Participants who received Vitamin D had a 17 percent reduced risk of falling, compared to participants who did not receive Vitamin D.
Vitamin D deficit doubles risk of stroke in whites, but not in blacks
Low levels of vitamin D, the essential nutrient obtained from milk, fortified cereals and exposure to sunlight, doubles the risk of stroke in whites, but not in blacks, according to a new report by researchers at Johns Hopkins.
Stroke is the nation's third leading cause of death, killing more than 140,000 Americans annually and temporarily or permanently disabling over half a million when there is a loss of blood flow to the brain.
Researchers say their findings, presented Nov. 15, 2010 at the American Heart Association's (AHA) annual Scientific Sessions in Chicago, back up evidence from earlier work at Johns Hopkins linking vitamin D deficiency to higher rates of death, heart disease and peripheral artery disease in adults.
The Hopkins team says its results fail to explain why African Americans, who are more likely to be vitamin D deficient due to their darker skin pigmentation's ability to block the sun's rays, also suffer from higher rates of stroke. Of the 176 study participants known to have died from stroke within a 14-year period, 116 were white and 60 were black. Still, African Americans had a 65 percent greater likelihood of suffering such a severe bleeding in or interruption of blood flow to the brain than whites, when age, other risk factors for stroke, and vitamin D deficiency were factored into their analysis.
"Higher numbers for hypertension and diabetes definitely explain some of the excess risk for stroke in blacks compared to whites, but not this much risk," says study co-lead investigator and preventive cardiologist Erin Michos, M.D., M.H.S., an assistant professor at the Johns Hopkins University School of Medicine and its Heart and Vascular Institute. "Something else is surely behind this problem. However, don't blame vitamin D deficits for the higher number of strokes in blacks."
Nearly 8,000 initially healthy men and women of both races were involved in the latest analysis, part of a larger, ongoing national health survey, in which the researchers compared the risk of death from stroke between those with the lowest blood levels of vitamin D to those with higher amounts. Among them, 6.6 percent of whites and 32.3 percent of blacks had severely low blood levels of vitamin D, which the experts say is less than 15 nanograms per milliliter.
"It may be that blacks have adapted over the generations to vitamin D deficiency, so we are not going to see any compounding effects with stroke," says Michos, who notes that African Americans have adapted elsewhere to low levels of the bone-strengthening vitamin, with fewer incidents of bone fracture and greater overall bone density than seen in Caucasians.
"In blacks, we may not need to raise vitamin D levels to the same level as in whites to minimize their risk of stroke" says Michos, who emphasizes that clinical trials are needed to verify that supplements actually do prevent heart attacks and stroke. In her practice, she says, she monitors her patients' levels of the key nutrient as part of routine blood work while also testing for other known risk factors for heart disease and stroke, including blood pressure, glucose and lipid levels.
Michos cautions that the number of fatal strokes recorded in blacks may not have been statistically sufficient to find a relationship with vitamin D deficits. And she points out that the study only assessed information on deaths from stroke, not the more common "brain incidents" of stroke, which are usually non-fatal, or even mini-strokes, whose symptoms typically dissipate in a day or so. She says the team's next steps will be to evaluate cognitive brain function as well as non-fatal and transient strokes and any possible tie-ins to nutrient deficiency.
Besides helping to keep bones healthy, vitamin D plays an essential role in preventing abnormal cell growth, and in bolstering the body's immune system. The hormone-like nutrient also controls blood levels of calcium and phosphorus, essential chemicals in the body. Shortages of vitamin D have also been tied to increased rates of breast cancer and depression in the elderly.
Michos recommends that people maintain good vitamin D levels by eating diets rich in such fish as salmon and tuna, consuming vitamin-D fortified dairy products, and taking vitamin D supplements. She also promotes brief exposure daily to the sun's vitamin D-producing ultraviolet light. And to those concerned about the cancer risks linked to too much time spent in the sun, she says as little as 10 to 15 minutes of daily exposure is enough during the summer months.
If vitamin supplements are used, Michos says that daily doses between 1,000 and 2,000 international units are generally safe and beneficial for most people, but that people with the severe vitamin D deficits may need higher doses under close supervision by their physician to avoid possible risk of toxicity.
The U.S. Institute of Medicine (IOM) previously suggested that an adequate daily intake of vitamin D is between 200 and 600 international units. However, Michos argues that this may be woefully inadequate for most people to raise their vitamin D blood levels to a healthy 30 nanograms per milliliter. The IOM has set up an expert panel to review its vitamin D guidelines, with new recommendations expected by the end of the year. Previous results from the same nationwide survey showed that 41 percent of men and 53 percent of women have unhealthy amounts of vitamin D, with nutrient levels below 28 nanograms per milliliter.
Less Vitamin D Means Higher Mortality After Heart Failure
Survival rates in heart failure patients with reduced levels of vitamin D are lower than in patients with normal levels. This is the finding of a major study carried out at University Medical Center, Groningen, Netherlands, according to a presentation at the European Society of Cardiology's Congress 2010 in Stockholm.
Results also suggest that low levels of vitamin D are associated with activation of the Renin Angiotensin System (RAS -- a pivotal regulatory system in heart failure) and an altered cytokine profile.
Vitamin D is produced by the skin when it is exposed to the natural Ultra Violet-B (UV-B) radiation from the sun. Low levels have long been known as the underlying mechanism of rickets however, in recent years, new studies have provided novel insight into the multiple vitamin's functions. It has been proved that most tissues and cells have a vitamin D receptor, and there is strong evidence that its presence plays a part in reducing the risk factor profiles of several chronic illnesses, such as common cancers, autoimmune diseases, kidney diseases, chronic infectious diseases, hypertension and apparently also heart failure.
"By showing that vitamin D is an independent predictor, we hoped to prove that it is a contributory factor to, rather than peripheral to, the development and prognosis of heart failure," said Ms. Licette Liu of the University Medical Center, Groningen. "With this new information, we then hope to provide better insight into the pathophysiology of heart failure."
Experiments with mice lacking the vitamin D receptor have shown typical signs of heart failure, while small-scale clinical studies have shown that low levels are a consistent factor amongst human heart failure patients. "There are several potential reasons for low vitamin D levels in heart failure patients, including the fact that they are often bedridden or house-bound due to their clinical symptoms" Ms. Liu explains. "This would lead to a serious deficiency, because 80-90 percent of vitamin D is obtained by UV-B radiation. Another factor is that the capacity of the skin to produce vitamin D declines with age, and as heart failure has a high incidence among elderly people, it is not entirely surprising to measure low levels. Furthermore, severe heart failure is associated with impaired renal function due to decreased blood supply. This may be responsible for a reduced synthesis of the active form of vitamin D, since the final step of conversion takes place in the kidneys. All of these factors may add to vitamin D deficiency in heart failure patients."
Observations in animal studies suggest that vitamin D is a negative regulator of the RAS, which is responsible for volume and blood pressure homeostasis and is a pivotal regulatory system in heart failure. Low levels may activate the RAS, which in turn may contribute to the development and progression of heart failure. There is also growing evidence that overproduction of several pro-inflammatory cytokines (and underproduction of anti-inflammatory cytokines) plays an important role in heart failure. Several studies have shown that vitamin D alters the cytokine profile and may therefore contribute to the inflammatory processes in heart failure.
In the current study, vitamin D concentration was assessed in plasma samples from 548 heart failure patients, using data supplied by the Coordinating study evaluating Outcomes of Advising and Counselling in Heart failure (COACH). Results showed that vitamin D concentration is associated with the prognosis of heart failure. Patients with lower concentrations had a higher risk of death or required re-hospitalisation, whereas patients with higher concentrations had lower survival risks for these endpoints. Further, significant correlations between vitamin D, and Plasma Renin Activity and C-Reactive Protein were found. These correlations suggest that the association between vitamin D and the prognosis in heart failure may be explained by activation of the RAS and an altered cytokine profile.
This is the first study in a large cohort of patients recruited due to hospitalisation for heart failure, in which the role of vitamin D has been determined, along with the roles of plasma renin activity and cytokines. Previous reports involved smaller study cohorts, and did not determine either plasma renin activity or cytokines, or they included patients who were referred routinely for coronary angiography at baseline.
The major limitation of this observational study was that bystander and indirect effects of variables could not be discounted. Therefore, a prospective randomised intervention study is necessary to investigate the effect of vitamin D on the RAS, cytokines profile and, finally, on the prognosis in heart failure patients. Ms. Liu concludes, "This study provides compelling evidence that a high vitamin D status is associated with improved survival in heart failure patients. Until an intervention study has been designed and completed, it seems that we should advise patients with heart failure to maintain appropriate vitamin D levels by taking supplements, by eating oily fish or eggs, or simply by exposure to sunlight."
Vitamin D Fights Asthma
According to an article published September, 2010 in Annals of Allergy, Asthma & Immunology, the scientific journal of the American College of Allergy, Asthma and Immunology (ACAAI): “There is a possible cause-and-effect relationship between vitamin D deficiency and uncontrolled asthma. Evidence suggests that vitamin D has a number of biologic factors that are important in regulating key mechanisms in asthma.”
Authors conducted a review of almost 60 years of literature on vitamin D and asthma. According to the article, vitamin D deficiency is associated with increased airway hyperresponsiveness, lower lung functions, and inferior asthma control. Vitamin D deficiency is more common with obesity, in African American ethnicity and westernization of countries reflecting a higher-risk population for asthma.
Selenium and vitamin D status reduce the effects of aging
New research in human volunteers has shown that molecular changes to our genes, known as epigenetic marks, are driven mainly by ageing but are also affected by what we eat.
The study showed that whilst age had the biggest effects on these molecular changes, selenium and vitamin D status reduced the accumulation of epigenetic changes, and high blood folate and obesity increased them. These findings support the idea that healthy ageing is affected by what we eat.
Researchers from the Institute of Food Research led by Dr Nigel Belshaw, working with Prof John Mathers and colleagues from Newcastle University, examined the cells lining the gut wall from volunteers attending colonoscopy clinic. The Institute of Food Research is strategically funded the Biotechnology and Biological Sciences Research Council and this study was also funded by the Food Standards Agency.
The study volunteers were free from cancer or inflammatory bowel disease and consumed their usual diet without any supplements. The researchers looked for specific epigenetic modifications of the volunteers’ genes that have been associated with the earliest signs of the onset of bowel cancer – an age-related disease. These epigenetic marks, known as DNA methylation, do not alter the genetic code but affect whether the genes are turned on or off. These methylation marks are transmitted when cells divide, and some have been associated with the development of cancer.
The investigators studied the relationship between the occurrence of these epigenetic marks at genes known to be affected in cancer, and factors including the volunteers’ age, sex, body size and the levels of some nutrients in the volunteers’ blood. The biggest influence on gene methylation was age. This fits with the fact that the biggest risk factor for bowel cancer is age, with risk increasing exponentially over 50 years old.
The findings, published in the journal Aging Cell, showed that men tended to have a higher frequency of these epigenetic changes than women, which is consistent with men being at a greater risk of bowel cancer. Volunteers with higher vitamin D status tended to show lower levels of methylation, and a similar effect was observed for selenium status. Again, this is consistent with the known links between higher vitamin D and selenium and reduced bowel cancer risk.
The B vitamin folate is essential for health, but in this study, high folate status was associated with increased levels of epigenetic changes linked with bowel cancer. These findings are consistent with some epidemiological studies suggesting that excessive folate intakes may increase risk in some people. The results of this study showing an association between folate status and epigenetic changes linked to cancer, together with those from another recent study by Nigel Belshaw’s group showing that, in cells grown in the laboratory, they could be induced by exposure to high levels of folic acid, emphasise the need for further research on optimal folate status in humans. The researchers intend to investigate the mechanism for the effect of folate on DNA methylation in a follow-up study.
Obesity is also a risk factor for bowel cancer. This study found relationships between body size (height, weight and waist circumference) and epigenetic changes. How excess body weight induces these epigenetic changes, and the consequences for gut health, are currently being investigated at IFR and in Newcastle University.
In summary, the results of this study support the hypothesis that ageing affects the epigenetic status of some genes and that these effects can be modulated by diet and body fatness.
Low vitamin D levels associated with cognitive decline
Older adults with low levels of vitamin D appear more likely to experience declines in thinking, learning and memory over a six-year period, according to a report in the July 12, 2010 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.
An estimated 40 percent to 100 percent of older adults in the United States and Europe are deficient in vitamin D, according to background information in the article. This deficiency has been linked to fractures, various chronic diseases and death. Vitamin D may help prevent the degeneration of brain tissue by having a role in formation of nervous tissue, maintaining levels of calcium in the body, or clearing of beta-amyloid, the substance that forms the brain plaques and tangles associated with Alzheimer's disease.
David J. Llewellyn, Ph.D., of University of Exeter, England, and colleagues assessed blood levels of vitamin D in 858 adults who were age 65 or older when the study began in 1998. Participants completed interviews and medical examinations and provided blood samples. At the beginning of the study and again after three and six years, they repeated three tests of cognitive function—one assessing overall cognition, one focusing on attention and one that places greater emphasis on executive function, or the ability to plan, organize and prioritize.
Participants who were severely deficient in vitamin D (having blood levels of 25-hydroxyvitamin D of less than 25 nanomoles per liter) were 60 percent more likely to have substantial cognitive decline in general over the six-year period and 31 percent more likely to experience declines on the test measuring executive function than those with sufficient vitamin D levels. "The association remained significant after adjustment for a wide range of potential confounders and when analyses were restricted to elderly subjects who were non-demented at baseline," the authors write. However, no significant association was seen for the test measuring attention.
"If future prospective studies and randomized controlled trials confirm that vitamin D deficiency is causally related to cognitive decline, then this would open up important new possibilities for treatment and prevention," the authors conclude.
(Arch Intern Med. 2010;170:1135-1141
New evidence shows low vitamin D levels lead to Parkinson's disease
A new study on vitamin D levels and Parkinson's disease risk points to the need for further research on whether vitamin D supplements can protect against the movement disorder, according to an editorial in the July 2010 issue of Archives of Neurology.
The author of the editorial is Marian Evatt, MD, assistant professor of neurology at Emory University School of Medicine and director of the Atlanta Veterans Affairs Medical Center's Movement Disorders Clinic.
The study, also reported in Archives of Neurology, is the first to show that low vitamin D levels can help predict whether someone will later develop Parkinson's disease. Researchers at Finland's National Institute for Health and Welfare measured vitamin D levels from more than 3000 people, using blood samples taken between 1978 and 1980, and then followed those people to see whether they developed Parkinson's. People with the lowest levels of vitamin D were three times more likely to develop Parkinson's, compared to the group with the highest levels.
Previous research had suggested a link between low vitamin D and Parkinson's, but whether this is a cause-and-effect relationship is unknown. Vitamin D may help protect the population of neurons gradually lost by people with Parkinson's disease, Evatt writes in her editorial.
Parkinson's disease affects nerve cells in several parts of the brain, particularly those that use the chemical messenger dopamine to control movement. The most common symptoms are tremor, stiffness and slowness of movement. These can be treated with oral replacement of dopamine.
Research on animals suggests that vitamin D may protect neurons that produce dopamine from toxins. Besides vitamin D levels, factors such as genetics and exposure to pesticides also are associated with the risk for developing Parkinson's disease.
Doctors have known for decades that vitamin D promotes calcium uptake and bone formation, but evidence is accumulating for additional roles regulating the immune system and the development of the nervous system. Humans can get vitamin D from exposure to sunlight or eating foods such as fatty fish or fortified foods such as milk and packaged cereals. People living at high latitudes tend to have less exposure to the sun; in the Finnish study, the average vitamin D level was about half of the currently recommended level.
Vitamin D levels are usually measured by looking at the stable, 25-hydroxy form; the current recommended level is 30-40 nanograms per milliliter of blood.
Evatt writes that public health authorities should consider raising the target vitamin D level above the current recommended target because of known benefits for bone health as well as potential benefits for the nervous system. Still, animal data suggests that too much vitamin D can also be harmful for the nervous system, and megadoses of vitamin D can induce hypercalcemia, or an excess of calcium in the blood.
"At this point, 30 ng/ml or more appears optimal for bone health in humans. However, researchers don't yet know what level is optimal for brain health or at what point vitamin D becomes toxic for humans, and this is a topic that deserves close examination," she says.
Low vitamin D linked to the metabolic syndrome in elderly people
A new study adds to the mounting evidence that older adults commonly have low vitamin D levels and that vitamin D inadequacy may be a risk factor for the metabolic syndrome, a condition that affects one in four adults. The results were presented at The Endocrine Society's 92nd Annual Meeting (2010) in San Diego.
"Because the metabolic syndrome increases the risk of diabetes and cardiovascular disease, an adequate vitamin D level in the body might be important in the prevention of these diseases," said study co-author Marelise Eekhoff, MD, PhD, of VU University Medical Center, Amsterdam.
The researchers found a 48 percent prevalence of vitamin D deficiency. The study consisted of a representative sample of the older Dutch population: nearly 1,300 white men and women ages 65 and older.
Nearly 37 percent of the total sample had the metabolic syndrome, a clustering of high blood pressure, abdominal obesity, abnormal cholesterol profile and high blood sugar.
Subjects with blood levels of vitamin D (serum 25-hydroxyvitamin D) lower than 50 nanomoles per liter, considered vitamin D insufficiency, were likelier to have the metabolic syndrome than those whose vitamin D levels exceeded 50. That increased risk especially stemmed from the presence of two risk factors for the metabolic syndrome: low HDL, or "good" cholesterol, and a large waistline.
There was no difference in risk between men and women, the authors noted.
The study included subjects who were participating in the Longitudinal Aging Study Amsterdam. Although the data were from 1995 and 1996, Eekhoff said they expect that vitamin D inadequacy remains prevalent among whites in the Netherlands.
Using follow-up data from 2009, the researchers plan to study how many of the subjects with low vitamin D levels developed diabetes.
"It is important to investigate the exact role of vitamin D in diabetes to find new and maybe easy ways to prevent it and cardiovascular disease," Eekhoff said.
Vitamin D Promotes Mental Agility in Elders
At a time when consumer interest in health-enhancing foods is high, Agricultural Research Service (ARS)-funded scientists have contributed to a limited but growing body of evidence of a link between vitamin D and cognitive function.
Cognitive function is measured by the level at which the brain is able to manage and use available information for activities of daily life. Alzheimer's disease, the most common form of age-related dementia, affects about 47 percent of adults aged 85 years or older in the United States. Identifying nutritional factors that lower cognitive dysfunction and help preserve independent living provides economic and public health benefits, according to authors.
The study, which was supported by ARS, the National Institutes of Health, and others, was led by epidemiologist Katherine Tucker with the Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) at Tufts University in Boston, Mass. Tucker collaborated with HNRCA laboratory directors Irwin Rosenberg, Bess Dawson-Hughes and colleagues.
Metabolic pathways for vitamin D have been found in the hippocampus and cerebellum areas of the brain involved in planning, processing, and forming new memories. This suggests that vitamin D may be implicated in cognitive processes.
The study involved more than 1,000 participants receiving home care. The researchers evaluated associations between measured vitamin D blood concentrations and neuropsychological tests. Elders requiring home care have a higher risk of not getting enough vitamin D because of limited sunlight exposure and other factors.
The participants, ages 65 to 99 years, were grouped by their vitamin D status, which was categorized as deficient, insufficient, or sufficient. Only 35 percent had sufficient vitamin D blood levels. They had better cognitive performance on the tests than those in the deficient and insufficient categories, particularly on measures of "executive performance," such as cognitive flexibility, perceptual complexity, and reasoning. The associations persisted after taking into consideration other variables that could also affect cognitive performance.
Vitamin D protects against diarrhea and colitis
A new study shows that patients with low vitamin D levels who develop Clostridia difficile (C. diff) have a higher recurrence rate and possibly higher hospital mortality. C. diff is a bacterium that causes diarrhea and more serious intestinal conditions such as colitis, and often occurs after taking antibiotics.
Previous studies have shown that normal levels of vitamin D are associated with improved outcomes in hospitalized patients, and conversely, low levels of vitamin D have been associated with higher mortality rate in hospitalized patients. Investigators at New York Hospital Queens –Weill Cornell Medical College, led by Moshe Rubin, MD, director of gastroenterology, sought to determine whether vitamin D levels are associated with a persons' ability to resolve their infection.
Researchers tracked 83 patients who had been admitted to the hospital who were then diagnosed with C. diff. They measured vitamin D levels in all of the patients, then followed their hospital course. Researchers noted how many patients were still alive after 30 days, and compared the outcome of patients with normal vitamin D levels to those with low levels. They found that up to 40 percent of people, especially in an older age group with multiple illnesses, died from some cause if they developed C. diff during that hospitalization.
Furthermore, while they may not die from C. diff, Dr. Rubin said it definitely adds a major complication that contributes to high mortality.
Researchers found that those with normal levels of vitamin D had a higher resolution rate, and a lower recurrence rate than those with low vitamin D levels. These findings are consistent with what is currently understood about vitamin D — it plays a role in immune function, may be an important factor in fighting infection, low levels seem to be a marker for not resolving diseases in general and it is associated with higher mortality rates.
Sixty-two patients were tracked for 30 days; 45 percent had normal vitamin D levels while 55 percent had low vitamin D levels. In the normal vitamin D group, they found 53 percent remained disease-free for 30 days, but in the group with low vitamin D levels, only 26 percent resolved their C. diff infections. Dr. Rubin noted that since this study was observational, it does not prove a cause and effect relationship between vitamin D levels and recurrence of C. diff, but it does identify an association.
Dr. Rubin said that since the study sample was relatively small, it should be repeated with a larger patient population to corroborate the data.
"We're starting to understand the importance of vitamin D in relation to overall health and to particular infections, like C. diff," said Dr. Rubin. "It's important to pay attention to nutritional issues and possibly even supplement vitamin D in patients with low levels to help fight serious infections."
Better vitamin D status could mean better quality of life for seniors
A limited number of studies point to the possibility that optimal intake of vitamin D (the "sunshine" vitamin) might help keep our muscles strong and preserve physical function. Although there are only few longitudinal studies investigating this relationship, their findings have been mixed. To help understand this diet-health association, Dr. Denise Houston from the Sticht Center on Aging at Wake Forest University and her collaborators studied the relationship between vitamin D status and physical function in a group of relatively healthy seniors living in Memphis, TN and Pittsburgh, PA. Their results were presented as part of the scientific program of the American Society for Nutrition, composed of the world's leading nutrition researchers, at the Experimental Biology 2010 meeting in Anaheim.
This study was part of the Health, Aging, and Body Composition (Health ABC) study initially designed to assess the associations among body composition, long-term health conditions, and mobility in older adults. For Houston's segment of the investigation, she studied 2788 seniors (mean age: ~75 years) for 4 years. At the beginning of the study, they assessed vitamin D status by analyzing each person's blood for 25-hydroxyvitamin D, a precursor for activated vitamin D. At baseline and then 2 and 4 years later, the research team then determined whether circulating 25-hydroxyvitamin D was related to the participants' physical function. Specifically, they looked at how quickly each participant could walk a short distance (6 meters) and rise from a chair five times as well as maintain his or her balance in progressively more challenging positions. Each participant was also put through a battery of tests assessing endurance and strength.
When the results were tabulated, participants with the highest levels of 25-hydroxyvitamin D had better physical function. And, although physical function declined over the course of the study, it remained significantly higher among those with the highest vitamin D levels at the beginning of the study compared to those with the lowest vitamin D levels. The scientists were not surprised to learn that, in general, vitamin D consumption was very low in this group of otherwise healthy seniors. In fact, more than 90% of them consumed less vitamin D than currently recommended, and many were relying on dietary supplements.
The good news: higher circulating 25-hydroxyvitamin D is related to better physical function in seniors. But it's impossible to tell from this type of research whether increasing vitamin D intake will actually lead to stronger muscles and preserve physical function. This is partly due to the fact that our bodies can make vitamin D if they get enough sunlight. So, it is possible that the participants with better physical function had higher vitamin D status simply because they were able to go outside more often. Indeed, the ominous "chicken-or-the-egg" question can only be answered by carefully controlled clinical intervention trials. Nonetheless, it is possible that getting more vitamin D from foods (like fortified milk and oily fish) or supplements will help maintain youth and vitality as we enjoy longer lifespans. As Houston points out: "Current dietary recommendations are based primarily on vitamin D's effects on bone health. It is possible that higher amounts of vitamin D are needed for the preservation of muscle strength and physical function as well as other health conditions. However, clinical trials are needed to definitively determine whether increasing 25-hydroxyvitamin D concentrations through diet or supplements has an effect on these non-traditional outcomes."
Low vitamin D levels associated with more asthma symptoms and medication use
Low levels of vitamin D are associated with lower lung function and greater medication use in children with asthma, according to researchers at National Jewish Health. In a paper published online in the Journal of Allergy & Clinical Immunology, Daniel Searing, MD, and his colleagues also reported that vitamin D enhances the activity of corticosteroids, the most effective controller medication for asthma.
"Asthmatic children in our study who had low levels of vitamin D were more allergic, had poorer lung function and used more medications," said Dr. Searing. "Conversely, our findings suggest that vitamin D supplementation may help reverse steroid resistance in asthmatic children and reduce the effective dose of steroids needed for our patients."
The researchers examined electronic medical records of 100 pediatric asthma patients referred to National Jewish Health. Overall, 47 percent of them had vitamin D levels considered insufficient, below 30 nanograms per milliliter of blood (ng/mL). Seventeen percent of the patients had levels below 20 ng/mL, which is considered deficient. These levels were similar to vitamin D levels found in the general population.
Patients low in vitamin D generally had higher levels of IgE, a marker of allergy, and responded positively to more allergens in a skin prick test. Allergies to the specific indoor allergens, dog and house dust mite, were higher in patients with low vitamin D levels. Low vitamin D also correlated with low FEV1, the amount of air a person can exhale in one second, and lower FEV1/FVC, another measure of lung function. Use of inhaled steroids, oral steroids and long-acting beta agonists were all higher in patients low in vitamin D.
"Our findings suggest two possible explanations," said senior author Donald Leung, MD, PhD. "It could be that lower vitamin D levels contribute to increasing asthma severity, which requires more corticosteroid therapy. Or, it may be that vitamin D directly affects steroid activity, and that low levels of vitamin D make the steroids less effective, thus requiring more medication for the same effect."
The researchers performed a series of laboratory experiments that indicated vitamin D enhances the action of corticosteroids. They cultured some immune cells with the corticosteroid dexamethasone alone and others with vitamin D first, then dexamethasone. The vitamin D significantly increased the effectiveness of dexamethasone. In one experiment vitamin D and dexamethasone together were more effective than 10 times as much dexamethasone alone.
The researchers also incubated immune-system cells for 72 hours with a staphylococcal toxin to induce corticosteroid resistance. Vitamin D restored the activity of dexamethasone.
"Our work suggests that vitamin D enhances the anti-inflammatory function of corticosteroids,' said Dr. Leung. "If future studies confirm these findings vitamin D may help asthma patients achieve better control of their respiratory symptoms with less medication."
Study links rheumatoid arthritis to vitamin D deficiency
Women living in the northeastern United States are more likely to develop rheumatoid arthritis (RA), suggesting a link between the autoimmune disease and vitamin D deficiency, says a new study led by a Boston University School of Public Health researcher.
In the paper, which appears online in the journal Environmental Health Perspectives, a spatial analysis led by Dr. Verónica Vieira, MS, DSc, associate professor of environmental health, found that women in states like Vermont, New Hampshire and southern Maine were more likely to report being diagnosed with RA.
"There's higher risk in the northern latitudes," Dr. Vieira said. "This might be related to the fact that there's less sunlight in these areas, which results in a vitamin D deficiency."
The study looked at data from the Nurses' Health Study, a long-term cohort study of U.S. female nurses. Looking at the residential addresses, health outcomes and behavioral risk factors for participants between 1988 and 2002, researchers based their findings on 461 women who had RA, compared to a large control group of 9,220.
RA is a chronic inflammatory disease that affects the lining of the joints, mostly in the hands and knees. This chronic arthritis is characterized by swelling and redness and can wear down the cartilage between bones. RA is two to three times more common in women than in men.
Although the cause of RA is unknown, the researchers wrote, earlier studies have shown that vitamin D deficiency, which can be caused by a lack of sunlight, has already been associated with a variety of other autoimmune diseases.
"A geographic association with northern latitudes has also been observed for multiple sclerosis and Crohn's disease, other autoimmune diseases that may be mediated by reduced vitamin D from decreased solar exposure and the immune effects of vitamin D deficiency," the authors wrote.
The authors said further research is needed to look into the relationship between vitamin D exposure and RA.
Dr. Vieira said she and her co-authors were somewhat surprised by the findings. A previous geographic study of RA had suggested an ecologic association with air pollution, she said.
"The results were unexpected," Dr. Vieira said. "Prior to the analysis, we were more interested in the relationship with air pollution. I hadn't given latitudes much thought."
In addition to the geographic variation, the study suggested that the timing of residency may influence RA risk. "Slightly higher odds ratios were observed for the 1988 analysis suggesting that long term exposure may be more important than recent exposure," the study said.
Studies find treating vitamin D deficiency significantly reduces heart disease risk
Preventing and treating heart disease in some patients could be as simple as supplementing their diet with extra vitamin D, according to two new studies
Preventing and treating heart disease in some patients could be as simple as supplementing their diet with extra vitamin D, according to two new studies at the Intermountain Medical Center Heart Institute in Murray, Utah.
Researchers at the Intermountain Medical Center Heart Institute last fall demonstrated the link between vitamin D deficiency and increased risk for coronary artery disease. These new studies show that treating vitamin D deficiency with supplements may help to prevent or reduce a person's risk for cardiovascular disease and a host of other chronic conditions. They also establish what level of vitamin D further enhances that risk reduction.
"Vitamin D replacement therapy has long been associated with reducing the risk of fractures and diseases of the bone," says Dr. J. Brent Muhlestein, MD, director of cardiovascular research at the Intermountain Medical Center Heart Institute. "But our findings show that vitamin D could have far greater implications in the treatment and reduction of cardiovascular disease and other chronic conditions than we previously thought."
For the first study, researchers followed two groups of patients for an average of one year each. In the first study group, over 9,400 patients, mostly female, reported low initial vitamin D levels, and had at least one follow up exam during that time period. Researchers found that 47 percent of the patients who increased their levels of vitamin D between the two visits showed a reduced risk for cardiovascular disease.
In the second study, researchers placed over 31,000 patients into three categories based on their levels of vitamin D. The patients in each category who increased their vitamin D levels to 43 nanograms per milliliter of blood or higher had lower rates of death, diabetes, cardiovascular disease, myocardial infarction, heart failure, high blood pressure, depression, and kidney failure. Currently, a level of 30 nanograms per milliliter is considered "normal."
Heidi May, PhD, a cardiovascular clinical epidemiologist with the Intermountain Medical Center Heart Institute, and one of the study's authors, says the link between low levels of vitamin D and increased risk for a variety of diseases is significant.
"It was very important to discover that the 'normal' levels are too low. Giving physicians a higher level to look for gives them one more tool in identifying patients at-risk and offering them better treatment," says Dr. May.
Dr. Muhlestein says the results of these studies will change the way he treats his patients.
"Although randomized trials would be useful and are coming, I feel there is enough information here for me to start treatment based on these findings," he says.
Treatment options in this case are simple, starting with a blood test to determine a patient's vitamin D level. If low levels are detected, supplements and/or increased exposure to sunlight may be prescribed.
Increasing vitamin D intake by 1000 to 5000 international units (IU) a day may be appropriate, depending on a patient's health and genetic risk, says Dr. Muhlestein. He says supplements are the best source of vitamin D because they are relatively inexpensive and can be found at almost any supermarket or drug store. Most supplements provide an average of 400 IU per tablet.
Vitamin D lowers kidney cancer risk in men
According to a new study, men employed in occupations with potential exposure to high levels of sunlight have a reduced risk of kidney cancer compared with men who were less likely to be exposed to sunlight at work. The study did not find an association between occupational sunlight exposure and kidney cancer risk in women. Published early online in CANCER, a peer-reviewed journal of the American Cancer Society, the study is the largest case-control study of kidney cancer to investigate the association with occupational sunlight exposure. The study, however, did not include information on non-occupational sunlight exposure and does not address directly whether sunlight exposure can help prevent kidney cancer.
Research suggests that vitamin D, which is obtained from sun exposure, some foods, and from supplements, may help prevent some cancers. Vitamin D is metabolized and most active within the kidneys. Because both the incidence of kidney cancer and the prevalence of vitamin D deficiency have increased over the past few decades, Sara Karami, PhD, of the National Cancer Institute in Rockville, MD, and her colleagues designed a study to explore whether occupational sunlight exposure is associated with kidney cancer risk.
The study included 1,097 patients with kidney cancer and 1,476 individuals without cancer from four Central and Eastern European countries. Demographic and lifetime occupational information was collected through in-person interviews and occupational sunlight exposure indices were estimated based on industry and job titles. The investigators observed a 24 percent to 38 percent reduction in kidney cancer risk with increasing occupational sunlight exposure among male participants in the study. No association between occupational sunlight exposure and kidney cancer risk was observed among females in the study.
The findings suggest that sunlight exposure may affect kidney cancer risk, although the authors have no explanation for the apparent differences in risk between men and women. They offer several hypotheses for the observed differences. Biological or behavioral differences between men and women may play a role. For example, hormonal differences may influence the body's response to sunlight exposure, females may have a higher tendency to use sunscreen on a regular basis, and men may be prone to working outdoors while shirtless. It is also possible that the observed gender differences in risk were due to confounding by other unmeasured kidney cancer risk factors, such as recreational sunlight exposure and physical activity levels.
While this study's findings raise the possibility of a link between sunlight exposure and kidney cancer risk, "they clearly need to be replicated in other populations and in studies that use better estimates of long-term ultraviolet exposure and vitamin D intake," said Dr. Karami.
Article: "Occupational sunlight exposure and risk of renal cell carcinoma." Sara Karami, Paolo Boffetta, Patricia Stewart, Nathaniel Rothman, Katherine L. Hunting, Mustafa Dosemeci, Sonja I. Berndt, Paul Brennan, Wong-Ho Chow, and Lee E. Moore. CANCER; Published Online: March 8, 2010 (DOI: 10.1002/cncr.24939).
Vitamin D Crucial To Activating Immune Defenses
Scientists at the University of Copenhagen have discovered that Vitamin D is crucial to activating our immune defenses and that without sufficient intake of the vitamin, the killer cells of the immune system – T cells - will not be able to react to and fight off serious infections in the body.
For T cells to detect and kill foreign pathogens such as clumps of bacteria or viruses, the cells must first be 'triggered' into action and 'transform' from inactive and harmless immune cells into killer cells that are primed to seek out and destroy all traces of a foreign pathogen.
The researchers found that the T cells rely on vitamin D in order to activate and they would remain dormant, 'naïve' to the possibility of threat if vitamin D is lacking in the blood.
Chemical Reaction that Enables Activation
In order for the specialized immune cells (T cells) to protect the body from dangerous viruses or bacteria, the T cells must first be exposed to traces of the foreign pathogen. This occurs when they are presented by other immune cells in the body (known as macrophages) with suspicious 'cell fragments' or 'traces' of the pathogen. The T cells then bind to the fragment and divide and multiply into hundreds of identical cells that are all focused on the same pathogen type. The sequence of chemical changes that the T cells undergo enables them to both be 'sensitized to' and able to deliver a targeted immune response.
Professor Carsten Geisler from the Department of International Health, Immunology and Microbiology explains that "when a T cell is exposed to a foreign pathogen, it extends a signaling device or 'antenna' known as a vitamin D receptor, with which it searches for vitamin D. This means that the T cell must have vitamin D or activation of the cell will cease. If the T cells cannot find enough vitamin D in the blood, they won't even begin to mobilize. "
T cells that are successfully activated transform into one of two types of immune cell. They either become killer cells that will attack and destroy all cells carrying traces of a foreign pathogen or they become helper cells that assist the immune system in acquiring "memory". The helper cells send messages to the immune system, passing on knowledge about the pathogen so that the immune system can recognize and remember it at their next encounter. T cells form part of the adaptive immune system, which means that they function by teaching the immune system to recognize and adapt to constantly changing threats.
Activating and Deactivating the Immune System
For the research team, identifying the role of vitamin D in the activation of T cells has been a major breakthrough. "Scientists have known for a long time that vitamin D is important for calcium absorption and the vitamin has also been implicated in diseases such as cancer and multiple sclerosis, but what we didn't realize is how crucial vitamin D is for actually activating the immune system – which we know now. "
The discovery, the scientists believe, provides much needed information about the immune system and will help them regulate the immune response. This is important not only in fighting disease but also in dealing with anti-immune reactions of the body and the rejection of transplanted organs. Active T cells multiply at an explosive rate and can create an inflammatory environment with serious consequences for the body. After organ transplants, e.g. T cells can attack the donor organ as a "foreign invader". In autoimmune disease, hypersensitive T cells mistake fragments of the body's own cells for foreign pathogens, leading to the body launching an attack upon itself.
The research team was also able to track the biochemical sequence of the transformation of an inactive T cell to an active cell, and thus would be able to intervene at several points to modulate the immune response. Inactive or 'naïve' T cells crucially contain neither the vitamin D receptor nor a specific molecule (PLC-gamma1) that would enable the cell to deliver an antigen specific response.
The findings, continues Professor Geisler "could help us to combat infectious diseases and global epidemics. They will be of particular use when developing new vaccines, which work precisely on the basis of both training our immune systems to react and suppressing the body's natural defenses in situations where this is important – as is the case with organ transplants and autoimmune disease."
Most Vitamin D is produced as a natural byproduct of the skin's exposure to sunlight. It can also be found in fish liver oil, eggs and fatty fish such as salmon, herring and mackerel or taken as a dietary supplement. No definitive studies have been carried out for the optimal daily dosage of vitamin D but as a large proportion of the population have very low concentrations of vitamin D in the blood, a number of experts recommend between 25-50mg micrograms a day.
The findings were published in Nature Immunology, (Vitamin D controls T cell antigen receptor signaling and activation of human T cells ) 10.1038/ni.1851, on 07 March, 2010.
Low Low levels of Vitamin D linked to muscle fat, decreased strength in young
There’s an epidemic in progress, and it has nothing to do with the flu. A ground-breaking study published in the March 2010 Journal of Clinical Endocrinology and Metabolism found an astonishing 59 per cent of study subjects had too little Vitamin D in their blood. Nearly a quarter of the group had serious deficiencies (less than 20 ng/ml) of this important vitamin. Since Vitamin D insufficiency is linked to increased body fat, decreased muscle strength and a range of disorders, this is a serious health issue.
“Vitamin D insufficiency is a risk factor for other diseases,” explains principal investigator, Dr. Richard Kremer, co-director of the Musculoskeletal Axis of the Research Institute of the MUHC. “Because it is linked to increased body fat, it may affect many different parts of the body. Abnormal levels of Vitamin D are associated with a whole spectrum of diseases, including cancer, osteoporosis and diabetes, as well as cardiovascular and autoimmune disorders.”
The study by Dr. Kremer and co-investigator Dr. Vincente Gilsanz, head of musculoskeletal imaging at the Children’s Hospital Los Angeles of the University of Southern California, is the first to show a clear link between Vitamin D levels and the accumulation of fat in muscle tissue – a factor in muscle strength and overall health. Scientists have known for years that Vitamin D is essential for muscle strength. Studies in the elderly have showed bedridden patients quickly gain strength when given Vitamin D.
The study results are especially surprising, because study subjects – all healthy young women living in California – could logically be expected to benefit from good diet, outdoor activities and ample exposure to sunshine – the trigger that causes the body to produce Vitamin D.
“We are not yet sure what is causing Vitamin D insufficiency in this group,” says Dr. Kremer who is also Professor of Medicine at McGill University. High levels of Vitamin D could help reduce body fat. Or, fat tissues might absorb or retain Vitamin D, so that people with more fat are likely to also be Vitamin D deficient.”
The results extend those of an earlier study by Dr. Kremer and Dr. Gilsanz, which linked low levels of Vitamin D to increased visceral fat in a young population. “In the present study, we found an inverse relationship between Vitamin D and muscle fat,” Dr. Kremer says. “The lower the levels of Vitamin D the more fat in subjects’ muscles.”
Vitamin D lifts mood during cold weather months
A daily dose of vitamin D lifts mood during cold weather months when days are short and more time is spent indoors.
“Vitamin D deficiency continues to be a problem despite the nutrient’s widely reported health benefits,” said Sue Penckofer, PhD, RN, professor, MNSON. “Chicago winters compound this issue when more people spend time away from sunlight, which is a natural source of vitamin D.”
Diet alone may not be sufficient to manage vitamin D levels. A combination of adequate dietary intake of vitamin D, exposure to sunlight, and treatment with vitamin D2 or D3 supplements can decrease the risk of certain health concerns. The preferred range in the body is 30 - 60 ng/mL of 25(OH) vitamin D.
Loyola faculty members plan to take vitamin D research a step further by evaluating whether weekly vitamin D supplements improve blood sugar control and mood in women with diabetes. Depression is associated with increased insulin resistance, so people with diabetes have a greater risk for the disease than those without depression. Women also tend to have greater rates of depression and poorer blood sugar control than men with diabetes.
“There is evidence to suggest that vitamin D supplementation may decrease insulin resistance,” said Dr. Penckofer. “If we can stabilize insulin levels, we may be able to simply and cost effectively improve blood sugar control and reduce symptoms of depression for these women.”
Loyola is currently enrolling women in this clinical trial. In order to enter the study, they must be 18 to 70 years of age, have stable type 2 diabetes, signs of depression and no other major medical illness. Eighty women with type 2 diabetes and signs of depression will be given a weekly dose of vitamin D (50,000 IU) for a period of six months. Study participants will be evaluated at three points during this time.
"Vitamin D has widespread benefits for our health and certain chronic diseases in particular," Dr. Penckofer said. "Our research may shed greater light on the role this nutrient plays in managing two conditions that impact millions of Americans. If proven to be successful, vitamin D may an important addition to care for diabetes and depression."
High levels of vitamin D in older people can reduce heart disease and diabetes
Middle aged and elderly people with high levels of vitamin D could reduce their chances of developing heart disease or diabetes by 43%, according to researchers at the University of Warwick.
A team of researchers at Warwick Medical School carried out a systematic literature review of studies examining vitamin D and cardiometabolic disorders. Cardiometabolic disorders include cardiovascular disease, type 2 diabetes mellitus and metabolic syndrome.
Vitamin D is a fat-soluble vitamin that is naturally present in some foods and is also produced when ultraviolet rays from sunlight strike the skin and trigger vitamin D synthesis. Fish such as salmon, tuna and mackerel are good sources of vitamin D, and it is also available as a dietary supplement.
Researchers looked at 28 studies including 99,745 participants across a variety of ethnic groups including men and women. The studies revealed a significant association between high levels of vitamin D and a decreased risk of developing cardiovascular disease (33% compared to low levels of vitamin D), type 2 diabetes (55% reduction) and metabolic syndrome (51% reduction).
The literature review, published in the journal Maturitas, was led by Johanna Parker and Dr Oscar Franco, Assistant Professor in Public Health at Warwick Medical School.
Dr Franco said: “We found that high levels of vitamin D among middle age and elderly populations are associated with a substantial decrease in cardiovascular disease, type 2 diabetes and metabolic syndrome.
“Targeting vitamin D deficiency in adult populations could potentially slow the current epidemics of cardiometabolic disorders.”
All studies included were published between 1990 and 2009 with the majority published between 2004 and 2009. Half of the studies were conducted in the United States, eight were European, two studies were from Iran, three from Australasia and one from India.
Vitamin D Supplements Could Fight Crohn's Disease
A new study has found that Vitamin D, readily available in supplements or cod liver oil, can counter the effects of Crohn's disease. John White, an endocrinologist at the Research Institute of the McGill University Health Centre, led a team of scientists from McGill University and the Universite de Montreal who present their findings about the inflammatory bowel disease in the Journal of Biological Chemistry test.
"Our data suggests, for the first time, that Vitamin D deficiency can contribute to Crohn's disease," says Dr. White, a professor in McGill's Department of Physiology, noting that people from northern countries, which receive less sunlight that is necessary for the fabrication of Vitamin D by the human body, are particularly vulnerable to Crohn's disease.
Vitamin D, in its active form (1,25-dihydroxyvitamin D), is a hormone that binds to receptors in the body's cells. Dr. White's interest in Vitamin D was originally in its effects in mitigating cancer. Because his results kept pointing to Vitamin D's effects on the immune system, specifically the innate immune system that acts as the body's first defense against microbial invaders, he investigated Crohn's disease. "It's a defect in innate immune handling of intestinal bacteria that leads to an inflammatory response that may lead to an autoimmune condition," stresses Dr. White.
Dr. White and his team found that Vitamin D acts directly on the beta defensin 2 gene, which encodes an antimicrobial peptide, and the NOD2 gene that alerts cells to the presence of invading microbes. Both Beta-defensin and NOD2 have been linked to Crohn's disease. If NOD2 is deficient or defective, it cannot combat invaders in the intestinal tract.
What's most promising about this genetic discovery, says Dr. White, is how it can be quickly put to the test. "Siblings of patients with Crohn's disease that haven't yet developed the disease might be well advised to make sure they're vitamin D sufficient. It's something that's easy to do, because they can simply go to a pharmacy and buy Vitamin D supplements. The vast majority of people would be candidates for Vitamin D treatment."
"This discovery is exciting, since it shows how an over-the-counter supplement such as Vitamin D could help people defend themselves against Crohn's disease," says Marc J. Servant, a professor at the Universite de Montreal's Faculty of Pharmacy and study collaborator. "We have identified a new treatment avenue for people with Crohn's disease or other inflammatory bowel diseases."
Low Vitamin D = stroke, heart disease and death
Study finds inadequate levels of Vitamin D may significantly increase risk of stroke, heart disease and death
While mothers have known that feeding their kids milk builds strong bones, a new study by researchers at the Heart Institute at Intermountain Medical Center in Salt Lake City suggests that Vitamin D contributes to a strong and healthy heart as well – and that inadequate levels of the vitamin may significantly increase a person's risk of stroke, heart disease, and death, even among people who've never had heart disease.
For more than a year, the Intermountain Medical Center research team followed 27,686 patients who were 50 years of age or older with no prior history of cardiovascular disease. The participants had their blood Vitamin D levels tested during routine clinical care. The patients were divided into three groups based on their Vitamin D levels – normal (over 30 nanograms per milliliter), low (15-30 ng/ml), or very low (less than 15 ng/ml). The patients were then followed to see if they developed some form of heart disease.
Researchers found that patients with very low levels of Vitamin D were 77 percent more likely to die, 45 percent more likely to develop coronary artery disease, and 78 percent were more likely to have a stroke than patients with normal levels. Patients with very low levels of Vitamin D were also twice as likely to develop heart failure than those with normal Vitamin D levels.
Findings from the study were presented at the American Heart Association's 2009 Scientific Conference/
"This was a unique study because the association between Vitamin D deficiency and cardiovascular disease has not been well-established," says Brent Muhlestein, MD, director of cardiovascular research of the Heart Institute at Intermountain Medical Center and one of the authors of the new study. "Its conclusions about how we can prevent disease and provide treatment may ultimately help us save more lives."
A wealth of research has already shown that Vitamin D is involved in the body's regulation of calcium, which strengthens bones — and as a result, its deficiency is associated with musculoskeletal disorders. Recently, studies have also linked Vitamin D to the regulation of many other bodily functions including blood pressure, glucose control, and inflammation, all of which are important risk factors related to heart disease. From these results, scientists have postulated that Vitamin D deficiency may also be linked to heart disease itself.
"Utah's population gave us a unique pool of patients whose health histories are different than patients in previous studies," Dr. Muhlestein says. "For example, because of Utah's low use of tobacco and alcohol, we were able to narrow the focus of the study to the effects of Vitamin D on the cardiovascular system."
The results were quite surprising and very important, says Heidi May, PhD, MS, an epidemiologist with the Intermountain Medical Center research team and one of the study authors.
"We concluded that among patients 50 years of age or older, even a moderate deficiency of Vitamin D levels was associated with developing coronary artery disease, heart failure, stroke, and death," she says. "This is important because Vitamin D deficiency is easily treated. If increasing levels of Vitamin D can decrease some risk associated with these cardiovascular diseases, it could have a significant public health impact. When you consider that cardiovascular disease is the leading cause of death in America, you understand how this research can help improve the length and quality of people's lives."
Vitamin D Fights Off Back Aches & Pains
Fight Off Back Aches & Pains This Winter With Extra Vitamin D
It’s no wonder that many people feel extra soreness and aches in their backs during winter months -- they’re often not getting enough vitamin D. The body makes vitamin D from the sun’s ultraviolet rays, so it’s known as the sunshine vitamin. However, even in the sunniest parts of America, this essential vitamin for keeping bones healthy is in short supply during late fall and winter.
Up to 8 out of 10 persons will have back pain in their lifetimes. In many cases, there is no evidence of any injury, disease, or bone problem like a slipped disk. An extensive review of clinical research in a report from Pain Treatment Topics found that help may be available from a surprising champion of pain relief – Vitamin D.
According to Stewart B. Leavitt, MA, PhD, Executive Director of Pain Treatment Topics and author of the report, “our examination of the research, which included numerous clinical studies, found that patients with chronic back pain usually had inadequate levels of vitamin D. When sufficient vitamin D supplementation was provided, their pain either vanished or was at least helped to a significant extent.”
The report, “Vitamin D – A Neglected ‘Analgesic’ for Chronic Musculoskeletal Pain,” which was peer-reviewed by a panel of experts, includes the following important points:
> Vitamin D is essential for calcium absorption and bone health. Among other things,inadequate vitamin D intake can result in a softening of bone surfaces, called osteomalacia, which causes pain. The lower back seems to be particularly vulnerable.
> In one study of 360 patients with chronic back pain, all of them were found to have inadequate levels of vitamin D. After taking vitamin D supplements for 3 months, symptoms were improved in 95% of the patients.
> The currently recommended adequate intake of vitamin D – up to 600 IU per day – is outdated and too low. According to newer research, most children and adults need at least 1000 IU per day, and persons with chronic back pain would benefit from 2000 IU or more per day of supplemental vitamin D3 (also called cholecalciferol).
> Vitamin D supplements interact with very few medicines or other agents, and are generally safe unless very high doses – such as 10,000 IU or more – are taken daily for a long period of time. However, it is always wise to check with a healthcare professional before starting a new dietary supplement.
> Vitamin D supplements are easy to take, usually have no side effects, and typically cost as little as 7 to 10 cents per day.
In conclusion, Leavitt stresses that vitamin D should not be viewed as a cure for all back pain conditions, and it is not necessarily a replacement for other pain-relief treatments. “While further research would be helpful,” he says, “extra vitamin D should be considered for all persons during winter months, and especially for those who have back aches and pains.”