Health Benefits of Vitamin D and Sunlight - Mortality Benefits

Low vitamin D linked to high risk of death from all causes including cancer and cardiovascular disease

The main source of vitamin D is its production in skin thanks to the sun. Women are more prone to low vitamin D than men - and due to differing weather conditions, concentrations vary in populations across the world.

Vitamin D deficiency is especially common among the elderly who often have less sun exposure, but it is unclear what effect the production of vitamin D has on death.

So researchers investigated the association of vitamin D with deaths from all-causes, cardiovascular diseases and cancer. They paid particular attention to differences between countries, sexes and age groups.

Data were taken from seven population-based cohorts from the US and across Europe. All study participants were aged 50-79.

Results reported in BMJ-British Medical Journal June 2014 show that there was no clear trend of vitamin D by age, but average levels were consistently lower among women than men. Average levels increased with education, were lowest in obese individuals and higher among subjects who exercised.

During 16 years of follow-up, there were 6,695 deaths in 26,018 patients - 2,624 from cardiovascular diseases and 2,227 from cancer.

An association was found between those with the lowest levels of vitamin D and death from cardiovascular disease - in people with and without a history of the disease- and deaths from cancer in those with a history of the disease. No association was found between low vitamin D levels and deaths from cancer in those without a history of the disease.

The researchers say this shows an important role of vitamin D in the prognosis of cancer, although they add "we cannot exclude reverse causality, that is, that the cancer might have led to low vitamin D levels." There was also a dose-response relationship which was unchanged after excluding patients with a history of cardiovascular disease and cancer.

The researchers say that death from all causes as a result of low vitamin D has "high public health relevance" and should be given high priority. They also ask whether levels of vitamin D in specific countries, different sexes and seasons "should be considered for defining vitamin D deficiency" due to its varying levels.

They conclude that those with the lowest levels of vitamin D had an association "with increased all-cause mortality, cardiovascular mortality, and cancer mortality (in subjects with a history of cancer)." They say these effects were consistent across countries, sexes, age groups, and time of the year when blood tests were done and that "variation by geographic region, sex and season might need to be taken into account."

Lower vitamin D level in blood linked to higher premature death rate

Researchers at the University of California, San Diego School of Medicine have found that persons with lower blood levels of vitamin D were twice as likely to die prematurely as people with higher blood levels of vitamin D.

The finding, published in the June 12, 2014 issue of American Journal of Public Health, was based on a systematic review of 32 previous studies that included analyses of vitamin D, blood levels and human mortality rates. The specific variant of vitamin D assessed was 25-hydroxyvitamin D, the primary form found in blood.

"Three years ago, the Institute of Medicine (IOM) concluded that having a too-low blood level of vitamin D was hazardous," said Cedric Garland, DrPH, professor in the Department of Family and Preventive Medicine at UC San Diego and lead author of the study. "This study supports that conclusion, but goes one step further. The 20 nanograms per milliliter (ng/ml) blood level cutoff assumed from the IOM report was based solely on the association of low vitamin D with risk of bone disease. This new finding is based on the association of low vitamin D with risk of premature death from all causes, not just bone diseases. "

Garland said the blood level amount of vitamin D associated with about half of the death rate was 30 ng/ml. He noted that two-thirds of the U.S. population has an estimated blood vitamin D level below 30 ng/ml.

"This study should give the medical community and public substantial reassurance that vitamin D is safe when used in appropriate doses up to 4,000 International Units (IU) per day," said Heather Hofflich, DO, professor in the UC San Diego School of Medicine's Department of Medicine.

"However, it's always wise to consult your physician when changing your intake of vitamin D and to have your blood level of 25-hydroxyvitamin D checked annually. Daily intakes above 4,000 IU per day may be appropriate for some patients under medical supervision."

The average age when the blood was drawn in this study was 55 years; the average length of follow-up was nine years. The study included residents of 14 countries, including the United States, and data from 566,583 participants.

Vitamin D deficiency increases mortality after cardiac arrest

Lack of vitamin D also increases poor brain function  after cardiac arrest  sevenfold

Vitamin D deficiency increases the risk of poor brain function after sudden cardiac arrest by seven-fold, according to research presented at Acute Cardiovascular Care 2014 by Dr Jin Wi from Korea. Vitamin D deficiency also led to a higher chance of dying after sudden cardiac arrest.

Acute Cardiovascular Care is the annual meeting of the Acute Cardiovascular Care Association (ACCA) of the European Society of Cardiology (ESC) and takes place 18-20 October in Geneva, Switzerland.

Dr Wi said: "In patients resuscitated after sudden cardiac arrest, recovery of neurological function is very important, as well as survival. Vitamin D deficiency has been reported to be related to the risk of having various cardiovascular diseases, including sudden cardiac arrest. We investigated the association of vitamin D deficiency with neurologic outcome after sudden cardiac arrest, a topic on which there is no information so far."

The researchers prospectively analysed clinical data from all unconscious patients resuscitated from sudden cardiac arrest of presumed cardiac cause at Severance Cardiovascular Hospital in Seoul, Korea. Neurologic outcome was assessed by the Cerebral Performance Category (CPC) score at 6 months after discharge.1 Good neurologic outcome was defined as a CPC score of 1 or 2, whereas poor neurological outcome was defined as a CPC score of 3 to 5. Vitamin D deficiency was defined as 25-hydroxyvitamin D less than 10 ng/mL.

The study included 53 patients. Bystander cardiopulmonary resuscitation (CPR) was performed in 41 patients (77%). The first monitored heart rhythm was shockable in 36 patients (68%) and non-shockable in 17 patients (32%). The average vitamin D level was 10.3 ng/mL and 31 patients (59%) were deficient.

Patients with a poor neurological outcome had a significantly lower vitamin D level (7.9 ng/mL) compared to those with a good neurological outcome (12.4 ng/mL) (p=0.002). The researchers found that 65% of patients with vitamin D deficiency had a poor neurological outcome at 6 months after discharge compared to 23% of patients with healthy vitamin D levels. They also found that 29% of patients with vitamin D deficiency had died at 6 months compared to none of the patients with good vitamin D levels (p=0.007).

Dr Wi said: "Patients with vitamin D deficiency were more likely to have a poor neurological outcome or die after sudden cardiac arrest than those who were not deficient. Nearly one-third of the patients who were deficient in vitamin D had died 6 months after their cardiac arrest, whereas all patients with sufficient vitamin D levels were still alive."

The researchers conducted a multivariate logistic analysis to assess the impact of a number of factors on neurological outcome after sudden cardiac arrest. They found that vitamin D deficiency independently predicted poor neurological outcome with an odds ratio of 7.13.

Dr Wi said: "Vitamin D deficiency increased the risk of poor neurological outcome after sudden cardiac arrest by 7-fold. The only factors that had a greater impact on poor neurological outcome were the absence of bystander CPR or having a first monitored heart rhythm that was non-shockable."

He added: "Our findings suggest that vitamin D deficiency should be avoided, especially in people with a high risk of sudden cardiac arrest. People are at higher risk if they have a personal or family history of heart disease including heart rhythm disorders, congenital heart defects and cardiac arrest. Other risk factors for cardiac arrest include smoking, obesity, diabetes, a sedentary lifestyle, high blood pressure and high cholesterol, and drinking too much alcohol."

Dr Wi continued: "Vitamin D is found in oily fish, such as salmon, sardines, and mackerel, eggs, fortified fat spreads, fortified breakfast cereals and powdered milk. Most of our vitamin D stores are made by the body when our skin reacts to sunlight."  

Low vitamin D levels linked to increased risks after noncardiac surgery

Death and serious complications more likely in patients with vitamin D deficiency, study suggests

August 15, 2014 – Patients with low blood levels of vitamin D are at increased risk of death and serious complications after noncardiac surgery, suggests a study in Anesthesia & Analgesia.

"Vitamin D concentrations were associated with a composite of in-hospital death, serious infections, and serious cardiovascular events," according to the new research by Dr Alparslan Turan and colleagues of the Cleveland Clinic. They believe their results warrant further study to see if giving vitamin D supplementation before surgery can reduce the risk of these adverse outcomes.

Lower Vitamin D Levels Linked to Higher Surgical Risk

The researchers analyzed the relationship between vitamin D level and surgical outcomes in approximately 3,500 patients who underwent operations other than heart surgery between 2005 and 2011. Only patients who had available data on vitamin D levels around the time of surgery—from three months before to one month afterward—were included in the study.

The concentration of vitamin D (specifically, 25-hydroxyvitamin D) in blood samples was analyzed as a risk factor for death, cardiovascular events, or serious infections while in the hospital. The analysis included adjustment for other factors such as demographic characteristics, medical conditions, and type and duration of surgery.

Most patients did not meet the recommended 25-hydroxyvitamin D concentration of greater than 30 nanograms per milliliter (ng/mL). The median vitamin D level was 23.5 ng/mL—more than 60 percent of patients were in the range of vitamin D insufficiency (10 to 30 ng/mL). Nearly 20 percent had vitamin D deficiency (less than 10 ng/mL).

"Higher vitamin D concentrations were associated with decreased odds of in-hospital mortality/morbidity," the researchers write. For each 5 ng/mL increase in 25-hydroxyvitamin D level, the combined risk of death, cardiovascular events, or serious infections decreased by seven percent.

Patients at the lowest level of 25-hydroxyvitamin D (less than 13 ng/mL) were at highest risk of death or serious complications. Those with higher vitamin D levels (up to 44 ng/mL) had about half the risk as those in the lowest group. The association with low vitamin D was statistically significant only for cardiovascular complications, although there were "strong trends" for mortality and infections.

Further Study Needed to Determine Cause and Effect

"Vitamin D deficiency is a global health problem," according to Dr Turan and coauthors. In addition to protective cardiovascular and neurological effects, vitamin D plays an important role in the immune system.

The high rates of vitamin D insufficiency and deficiency in the surgical patients studied are consistent with previous findings in the general population. In recent years, studies have suggested that vitamin D levels may affect a wide range of health outcomes.

Patients undergoing surgery are at risk of cardiovascular and infectious complications, both of which may be aggravated by vitamin D deficiency. Previous studies found no increased risk of adverse outcomes related to vitamin D levels in patients undergoing cardiac surgery. It may be that the tissue injury and inflammation associated with heart surgery overwhelms any potential protective effect of vitamin D.

However, Dr Turan and colleagues note that their study had some important limitations of their study—especially the fact that it included only patients who had recent measurements of vitamin D levels. They may represent a less-healthy group, introducing a potential source of selection bias.

The study can't determine whether there is any cause-and-effect relationship between vitamin D levels and the risk of adverse outcomes. Dr Turan and colleagues suggest a formal randomized trial to evaluate whether preoperative vitamin D supplementation can reduce the risk of serious complications and death after surgery.

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.

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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 ntiaeffects 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."

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 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 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 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."

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 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 study accepted for published 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.

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."

Sunshine could benefit health and prolong life

Exposing skin to sunlight may help to reduce blood pressure, cut the risk of heart attack and stroke – and even prolong life, a study suggests.

Researchers have shown that when our skin is exposed to the sun's rays, a compound is released in our blood vessels that helps lower blood pressure.

The findings suggest that exposure to sunlight improves health overall, because the benefits of reducing blood pressure far outweigh the risk of developing skin cancer.

The study has been carried out by the University of Edinburgh.

Heart disease and stroke linked to high blood pressure are estimated to lead to around 80 times more deaths than those from skin cancer, in the UK.

Production of this pressure-reducing compound – called nitric oxide – is separate from the body's manufacture of vitamin D, which rises after exposure to sunshine. Until now it had been thought to solely explain the sun's benefit to human health, the scientists add.

Researchers studied the blood pressure of 24 volunteers who sat beneath tanning lamps for two sessions of 20 minutes each. In one session, the volunteers were exposed to both the UV rays and the heat of the lamps. In the other, the UV rays were blocked so that only the heat of the lamps affected the skin.

The results showed that blood pressure dropped significantly for one hour following exposure to UV rays, but not after the heat-only sessions. Scientists say that this shows that it is the sun's UV rays that lead to health benefits. The volunteers' vitamin D levels remained unaffected in both sessions.

Dr Richard Weller, Senior Lecturer in Dermatology at the University of Edinburgh, said: "We suspect that the benefits to heart health of sunlight will outweigh the risk of skin cancer. The work we have done provides a mechanism that might account for this, and also explains why dietary vitamin D supplements alone will not be able to compensate for lack of sunlight.

"We now plan to look at the relative risks of heart disease and skin cancer in people who have received different amounts of sun exposure. If this confirms that sunlight reduces the death rate from all causes, we will need to reconsider our advice on sun exposure."