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Vitamin D
may play key role in preventing macular degeneration
Vitamin D has been studied extensively in relation to bone
health as well as cancer. Now, a team led by a researcher at the University at
Buffalo has discovered that vitamin D may play a significant role in eye
health, specifically in the possible prevention of age-related macular
degeneration, or AMD, among women who are more genetically prone to developing
the sight-damaging disease.
In a paper published in JAMA Ophthalmology
online, Amy Millen, associate professor of epidemiology and environmental
health in UB's School of Public Health and Health Professions, and her team
found that women who are deficient in vitamin D and have a specific high-risk
genotype are 6.7 times more likely to develop AMD than women with sufficient
vitamin D status and no high risk genotype.
"Most people have heard that you should eat carrots to
help your vision. However, there appear to be many other ways that adequate
nutrition can support eye health. Having adequate vitamin D status may be one
of them," says Millen, PhD, the study's lead author. "This is not a
study that can, alone, prove a causal association, but it does suggest that if
you're at high genetic risk for AMD, having a sufficient vitamin D status might
help reduce your risk."
"To our knowledge, this is the first study that's
looked at the interaction between genetic risk and vitamin D status in the
context of age-related eye disease," adds Millen.
Macular degeneration is characterized by the deterioration
of the macula, a small part of the central retina where the eye's
photoreceptors (rods and cones) are most highly concentrated. The leading cause
of legal blindness, macular degeneration affects more than 10 million Americans
-- more than cataracts and glaucoma combined -- according to the American
Macular Degeneration Foundation. The disease affects a person's central vision,
which is needed for common tasks such as reading and driving. The effect is
similar to that of a rain drop on the center of a camera lens.
Researchers analyzed data compiled on 1,230 women ages 54 to
74 who participated in the Carotenoids in Age-related Eye Disease Study
(CAREDS), which is an ancillary study of the Women's Health Initiative (WHI)
Observational Study (OS). The WHI OS is a major National Institutes of
Health-funded research program aimed at addressing the most common causes of
death, disability and poor quality of life in postmenopausal women. UB is one
of 40 WHI centers nationally. CAREDS was conducted among participants at three
of the centers: University of Wisconsin (Madison), the University of Iowa (Iowa
City) and the Kaiser Center for Health Research (Portland, Oregon).
Researchers were able to determine participants' vitamin D
status by analyzing serum samples for a vitamin D biomarker, 25-hydroxyvitamin
D [25(OH)D], which provided a glimpse into vitamin D intake through all
sources: diet, supplements and sunlight.
Human skin can synthesize vitamin D when exposed to ultraviolet
light, Millen explains. However, for many people, 15 to 30 minutes a day with
10 percent of their skin exposed might be sufficient. In winter months, when
there is a lower solar angle, sun exposure may not be not sufficient to
maintain blood level for people who live north of a line from about Washington,
D.C., to Los Angeles. At these times and locations, dietary intake may be
needed. Dietary sources of vitamin D include fortified foods such as milk and
foods that naturally contain vitamin D such as fatty fish like salmon and
mackerel.
"Macular degeneration has been found to be strongly
associated with genetic risk," Millen says. Among many genes linked to
AMD, one of the strongest is a specific genetic variant (Y402H) in the
complement factor H gene, called CFH for short. This gene codes for the CFH
protein that is involved in the body's immune response to destroy bacteria and
viruses.
Inflammation is believed to be involved in the development
of macular degeneration.
"People who have early stage AMD develop drusen, lipid
and protein deposits that build up in the eye. Your body sees this drusen as a
foreign substance and attacks it, in part via the complement cascade
response," explains Millen. "CFH is one of the proteins involved in
this response. We see more AMD in people who have certain variants in the gene
which encodes a form of this CFH protein that is associated with a more
aggressive immune response."
Vitamin D shows promise for protecting against macular
degeneration because of its anti-inflammatory and antiangiogenic properties;
antiangiogenic refers to slowing the growth of new blood vessels, often seen in
late stages of AMD.
"Our thinking was, if a person's vitamin D status is
better, would it reduce the immune response to drusen? We wanted to understand
if the association between vitamin D and AMD differed depending on a person's
genetic risk for AMD," says Millen. "Our study suggests that being
deficient for vitamin D may increase one's risk for AMD, and that this increased
risk may be most profound in those with the highest genetic risk for this
specific variant in the CFH protein."
The study results, however, shouldn't prompt people to run
to the nearest grocery store to purchase vitamin D supplements.
"Our message is not that achieving really high levels
of vitamin D are good for the eye, but that having deficient vitamin D levels
may be unhealthy for your eyes," Millen says.
Although the odds of having AMD was higher in women who were
deficient for vitamin D, with 25(OH)D levels below 12 ng/mL (30 nmol/L),
increasing vitamin D levels beyond 12 ng/mL did not further lower the odds of
AMD to any meaningful extent, she explains.
"This study supports a role for vitamin D in eye
health. That's significant because when the Institute of Medicine's report on
the dietary reference intakes for vitamin D and calcium were released in 2011,
the committee could only make conclusions about D related to bone health,"
says Millen. "There wasn't enough evidence at that time to make any recommendation
based on D status and other outcomes beyond bone health."
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.
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.
Vitamin D
Fights Off Back Aches & Pains
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.”
Vitamin
D supplementation for prevention and possibly for treatment of autism
A new study by Rhonda Patrick, PhD and
Bruce Ames, PhD of Children's Hospital Oakland Research Institute (CHORI)
demonstrates the impact that Vitamin D may have on social behavior associated
with Autism Spectrum Disorder (ASD). Dr. Patrick and Dr. Ames show that
serotonin, oxytocin, and vasopressin, three brain hormones that affect social
behavior, are all activated by vitamin D hormone. Autism, which is
characterized by abnormal social behavior, has previously been linked to low
levels of serotonin in the brain and to low vitamin D levels, but no mechanism
has linked the two until now.
In this study, Dr. Patrick and Dr. Ames
show that vitamin D hormone activates the gene that makes the enzyme tryptophan
hydroxylase 2 (TPH2), that converts the essential amino acid tryptophan, to
serotonin in the brain. This suggests that adequate levels of vitamin D may be required
to produce serotonin in the brain where it shapes the structure and wiring of
the brain, acts as a neurotransmitter, and affects social behavior. They also
found evidence that the gene that makes the enzyme tryptophan hydroxylase 1
(TPH1) is inhibited by vitamin D hormone, which subsequently halts the
production of serotonin in the gut and other tissues, where when found in
excess it promotes inflammation.
This mechanism explains many of the
known, but previously not understood, facts about autism including: 1) the
"serotonin anomaly" low levels of serotonin in the brain and high
levels in the blood of autistic children; 2) the preponderance of male over
female autistic children: estrogen, a similar steroid hormone, can also boost
the brain levels of serotonin in girls; 3) the presence of autoimmune
antibodies to the fetal brain in the mothers of autistic children: vitamin D
regulates the production of regulatory T-cells via repression of TPH1. The
Patrick/Ames mechanism is relevant to the prevention of autism, and likely its
treatment.
The current guidelines for adequate
vitamin D levels are concentrations above 30 ng/ml. Most Americans' vitamin D
is made in the skin from exposure to UVB radiation; however, melanin pigment
and sunscreen inhibit this action. This is an important cause of the well-known
widespread vitamin D deficiency among dark-pigmented Americans, particularly
those living in Northern latitudes. The most recent National Health and
Examination survey reports that greater than 70% of U.S. population does not
meet this requirement and that adequate vitamin D levels have plummeted over
the last couple of decades. This precipitous drop in adequate levels of vitamin
D in the US is concurrent with the rise in autism rates.
The study suggests dietary intervention
with vitamin D, tryptophan and omega 3 fatty acids would boost brain serotonin
concentrations and help prevent and possibly ameliorate some of the symptoms
associated with ASD without side effects. There is little vitamin D present in
food and fortification is still inadequate as is the amount in most
multivitamin and prenatal supplements. Vitamin D supplements are inexpensive
and offer a simple solution to raise vitamin D levels to an adequate status. In
addition, vitamin D levels should be routinely measured in everyone and should
become a standard procedure in prenatal care.
Vitamin D
deficiency may compromise immune function
Older individuals who are vitamin D
deficient also tend to have compromised immune function, according to new
research accepted for publication in the Endocrine Society's Journal of
Clinical Endocrinology & Metabolism (JCEM).
Vitamin D plays an important role in
helping the body absorb calcium needed for healthy bones. The skin naturally
produces vitamin D when it is exposed to sunlight. People also obtain smaller
amounts of the vitamin through foods, such as milk fortified with vitamin D.
More than 1 billion people worldwide are estimated to have deficient levels of
vitamin D due to limited sunshine exposure.
"Our data suggest vitamin D may be
involved in maintaining the health of the immune system as well as the skeletal
system," said one of the study's authors, Mary Ward, PhD, of the
University of Ulster in Coleraine, U.K. "This study is the first to find a
connection between vitamin D levels and inflammation in a large sample of older
individuals."
The observational study of 957 Irish
adults who were at least 60 years old examined vitamin D levels as well as
biomarkers of inflammation. Participants who were vitamin D deficient were more
likely to have high levels of these biomarkers, which are linked to
cardiovascular disease and inflammatory conditions such as multiple sclerosis
and rheumatoid arthritis.
"The results indicate immune
function may be compromised in older individuals with vitamin D
deficiency," Ward said. "Ensuring older individuals have optimal
vitamin D levels may be a way to boost immune function in this population, but
this needs to be confirmed through additional studies."
Low vitamin D
levels raise anemia risk in children
Low levels of the "sunshine"
vitamin D appear to increase a child's risk of anemia, according to new
research led by investigators at the Johns Hopkins Children's Center. The
study, published online Oct. 10 , 2013 in the Journal of Pediatrics, is believed to be the first one to
extensively explore the link between the two conditions in children.
The researchers caution that their
results are not proof of cause and effect, but rather evidence of a complex
interplay between low vitamin D levels and hemoglobin, the oxygen-binding
protein in red blood cells. The investigators say several mechanisms could
account for the link between vitamin D and anemia, including vitamin D's
effects on red blood cell production in the bone marrow, as well as its ability
to regulate immune inflammation, a known catalyst of anemia.
To capture the interaction between the
two conditions, researchers studied blood samples from more than 10,400
children, tracking levels of vitamin D and hemoglobin. Vitamin D levels were
consistently lower in children with low hemoglobin levels compared with their
non-anemic counterparts, the researchers found. The sharpest spike in anemia
risk occurred with mild vitamin D deficiency, defined as vitamin D levels below
30 nanograms per milliliter (ng/ml). Children with levels below 30 ng/ml had
nearly twice the anemia risk of those with normal vitamin D levels. Severe
vitamin D deficiency is defined as vitamin D levels at or below 20 ng/ml. Both
mild and severe deficiency requires treatment with supplements.
When investigators looked at anemia and
vitamin D by race, an interesting difference emerged. Black children had higher
rates of anemia compared with white children (14 percent vs. 2 percent) and
considerably lower vitamin D levels overall, but their anemia risk didn't rise
until their vitamin D levels dropped far lower than those of white children.
The racial difference in vitamin D levels and anemia suggests that current
therapeutic targets for preventing or treating these conditions may warrant a
further look, the researchers say.
"The clear racial variance we saw in
our study should serve as a reminder that what we may consider a pathologically
low level in some may be perfectly adequate in others, which raises some
interesting questions about our current one-size-fits-all approach to treatment
and supplementation," says lead investigator Meredith Atkinson, M.D.,
M.H.S., a pediatric kidney specialist at the Johns Hopkins Children's Center.
Untreated, chronic anemia and vitamin D
deficiency can have wide-ranging health consequences, including organ damage,
skeletal deformities and frequent fractures, and lead to premature osteoporosis
in later life.
Long known for its role in bone
development, vitamin D has recently been implicated in a wide range of
disorders. Emerging evidence suggests that low vitamin D levels may play a role
in the development of certain cancers and heart disease and lead to suppressed
immunity, the researchers note.
Anemia, which occurs when the body
doesn't have enough oxygen-carrying red blood cells, is believed to affect one
in five children at some point in their lives, experts say. Several large-scale
studies have found severe vitamin D deficiency in about a tenth of U.S. children,
while nearly 70 percent have suboptimal levels.
Low vitamin D
linked to fatty liver disease in children
A UK study investigating the link between
low vitamin D status and non-alcoholic fatty liver disease (NAFLD) in British
children has identified a genetic variant associated with the disease's
severity.
The research, conducted by the King's
College Hospital Paediatric Liver Centre and the University of Surrey's School
of Biosciences and Medicine, and funded by the Children's Liver Disease
Foundation retrospectively analysed the medical records of 120 paediatric
patients with NAFLD.
The findings could carry significant
implications for UK clinicians in light of the nation's rising number of
childhood NAFLD cases. High levels of vitamin D deficiency and increasing
numbers of rickets cases are thought to be due to the obesity epidemic, more
children increasingly choosing to play indoors rather than outside and the
excessive use of sun-creams.
EASL's Educational Councillor Professor
Jean-Francois Dufour of the University Clinic for Visceral Surgery and
Medicine, University of Bern, Switzerland said: "The data support recent
research that revealed an association between low vitamin D status and
incidence of NAFLD and is an important development in helping clinicians better
understand the growing rate of NAFLD in children throughout the western
world."
"Identifying a gene that impacts or
alters the disease is a step in the right direction and could potentially lead
to the development of new treatments or diagnostic techniques to address this
growing issue," Professor Dufour continued. "More research into this
field is warranted and I look forward to seeing future developments over
time."
NAFLD is the term used to describe fat
build-up in liver cells in people who do not drink alcohol excessively. NAFLD
is rapidly becoming the most common liver disease worldwide and is the most
common persistent liver disorder in western countries and is estimated to
affect up to 10% of Europe's paediatric population.[The disease has an
estimated overall prevalence of 20% to 30% across Europe.[
Patients were found to have low vitamin D
blood levels throughout the entire year, not just in the winter months, plus
the majority of samples were found to be deficient or insufficient in vitamin D
status compared to national UK and US health standards. The study also detected
a variant of the NADSYN1 gene that was associated with NAFLD severity in
patients.
Vitamin
D may reduce risk of uterine fibroids, according to NIH study
Women who had sufficient amounts of
vitamin D were 32 percent less likely to develop fibroids than women with
insufficient vitamin D, according to a study from researchers at the National
Institutes of Health.
Fibroids, also known as uterine
leiomyomata, are noncancerous tumors of the uterus. Fibroids often result in
pain and bleeding in premenopausal women, and are the leading cause of
hysterectomy in the United States.
The study of 1,036 women, aged 35-49,
living in the Washington, D.C., area from 1996 to 1999, was led by Donna Baird,
Ph.D., a researcher at the National Institute of Environmental Health Sciences
(NIEHS), part of NIH. Baird and her collaborators at The George Washington
University and the Medical University of South Carolina screened participants
for fibroids using ultrasound. They used blood samples to measure the primary
circulating form of vitamin D, known as 25-hydroxy D. Those with more than 20
nanograms per milliliter of 25-hydroxy D were categorized as sufficient, though
some experts think even higher levels may be required for good health. The body
can make vitamin D when the skin is exposed to the sun, or vitamin D can come
from food and supplements.
Study participants also completed a
questionnaire on sun exposure. Those who reported spending more than one hour
outside per day also had a decreased risk of fibroids. The estimated reduction
was 40 percent. Although fewer black than white participants had sufficient
25-hydroxy D levels, the estimated reduction in prevalence of fibroids was
about the same for both ethnic groups.
"It would be wonderful if something
as simple and inexpensive as getting some natural sunshine on their skin each
day could help women reduce their chance of getting fibroids," said Baird.
Baird also noted that, though the
findings are consistent with laboratory studies, more studies in women are
needed. Baird is currently conducting a study in Detroit to see if the findings
from the Washington, D.C., study can be replicated. Other NIEHS in-house
researchers, led by Darlene Dixon, D.V.M., Ph.D., are learning more about
fibroid development, by examining tissue samples from study participants who
had surgery for fibroids.
"This study adds to a growing body
of literature showing the benefits of vitamin D," said Linda Birnbaum,
Ph.D., director of NIEHS and the National Toxicology Program.
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
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
deficiency raises risk of schizophrenia diagnosis
Vitamin
D-deficient individuals are twice as likely to be diagnosed with schizophrenia
as people who have sufficient levels of the vitamin, according to a new study
published in the Endocrine Society's Journal
of Clinical Endocrinology & Metabolism.
Vitamin D helps the body absorb calcium
and is needed for bone and muscle health. The skin naturally produces this
vitamin after exposure to sunlight. People also obtain smaller amounts of the
vitamin through foods, such as milk fortified with vitamin D. More than 1
billion people worldwide are estimated to have deficient levels of vitamin D
due to limited sunshine exposure.
Schizophrenia is a mental illness with
symptoms that can include delusions and hallucinations. Since schizophrenia is
more prevalent in high latitudes and cold climates, researchers have theorized
vitamin D may be connected to the disorder.
"This is the first comprehensive
meta-analysis to study the relationship between the two conditions," said
one of the study's authors, Ahmad Esmaillzadeh, PhD, of the Isfahan University
of Medical Sciences in Isfahan, Iran. "When we examined the findings of
several observational studies on vitamin D and schizophrenia, we found people
with schizophrenia have lower vitamin D levels than healthy people. Vitamin D
deficiency is quite common among people with schizophrenia."
The researchers reviewed the findings of
19 observational studies that assessed the link between vitamin D and
schizophrenia. Combined, the studies looked at vitamin D levels and the mental
health of 2,804 adult participants. The studies used blood tests to determine
each participant's vitamin D levels.
The meta-analysis found that people with
schizophrenia had significantly lower levels of vitamin D in the blood compared
to the control groups. The average difference in vitamin D levels between
schizophrenic patients and control participants was -5.91 ng/ml. People with
vitamin D deficiency were 2.16 times more likely to have schizophrenia than
those with sufficient vitamin D in their bloodstreams. In addition, 65 percent
of the participants who had schizophrenia also were vitamin D deficient.
"There is a growing trend in the
nutrition science field to consider vitamin D and its relationship to
conditions such as diabetes, cancer, heart disease and depression,"
Esmaillzadeh said. "Our findings support the theory that vitamin D may
have a significant impact on psychiatric health. More research is needed to
determine how the growing problem of vitamin D deficiency may be affecting our
overall health."
Low vitamin D levels linked to increased
risks after noncardiac surgery
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.
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. 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.
