Vitamin D supplements may reduce risk of serious cardiovascular events in older people

by British Medical Journal

Credit: Pixabay/CC0 Public Domain

Vitamin D supplements may reduce the risk of major cardiovascular events such as heart attacks among people aged over 60, finds a clinical trial published by The BMJ.

09 Jul 2023--The researchers stress that the absolute risk difference was small, but say this is the largest trial of its kind to date, and further evaluation is warranted, particularly in people taking statins or other cardiovascular disease drugs.

Cardiovascular disease (CVD) is a general term for conditions affecting the heart or blood vessels and is one of the main causes of death globally. CVD events such as heart attacks and strokes are set to increase as populations continue to age and chronic diseases become more common.

Observational studies have consistently shown a link between vitamin D levels and CVD risk, but randomized controlled trials have found no evidence that vitamin D supplements prevent cardiovascular events, possibly due to differences in trial design that can affect results.

To address this uncertainty, researchers in Australia set out to investigate whether supplementing older adults with monthly doses of vitamin D alters the rate of major cardiovascular events.

Their D-Health Trial was carried out from 2014 to 2020 and involved 21,315 Australians aged 60-84 who randomly received one capsule of either 60,000 IU vitamin D (10,662 participants) or placebo (10,653 participants) taken orally at the beginning of each month for up to five years.

Participants with a history of high calcium levels (hypercalcemia), overactive thyroid (hyperparathyroidism), kidney stones, soft bones (osteomalacia), sarcoidosis, an inflammatory disease, or those already taking more than 500 IU/day vitamin D were excluded.

Data on hospital admissions and deaths were then used to identify major cardiovascular events, including heart attacks, strokes, and coronary revascularisation (treatment to restore normal blood flow to the heart).

The average treatment duration was five years and more than 80% of participants reported taking at least 80% of the study tablets.

During the trial, 1,336 participants experienced a major cardiovascular event (6.6% in the placebo group and 6% in the vitamin D group).

The rate of major cardiovascular events was 9% lower in the vitamin D compared with the placebo group (equivalent to 5.8 fewer events per 1,000 participants).

The rate of heart attack was 19% lower and the rate of coronary revascularization was 11% lower in the vitamin D group, but there was no difference in the rate of stroke between the two groups.

There was some indication of a stronger effect in those who were using statins or other cardiovascular drugs at the start of the trial, but the researchers say these results were not statistically significant.

Overall, the researchers calculate that 172 people would need to take monthly vitamin D supplements to prevent one major cardiovascular event.

The researchers acknowledge that there may be a small underestimate of events and say the findings may not apply to other populations, particularly those where a higher proportion of people are vitamin D deficient. However, this was a large trial with extremely high retention and adherence, and almost complete data on cardiovascular events and mortality outcomes.

As such, they say their findings suggest that vitamin D supplementation may reduce the risk of major cardiovascular events. "This protective effect could be more marked in those taking statins or other cardiovascular drugs at baseline," they add, and they suggest further evaluation is needed to help to clarify this issue.

"In the meantime, these findings suggest that conclusions that vitamin D supplementation does not alter risk of cardiovascular disease are premature," they conclude.

More information: Vitamin D supplementation and major cardiovascular events: D-Health randomised controlled trial, The BMJ (2023). DOI: 10.1136/bmj-2023-075230, www.bmj.com/content/381/bmj-2023-075230

 

Study casts more doubt on use of high-dose vitamin D pills

by LAURAN NEERGAARD

Credit: CC0 Public Domain

More research suggests it's time to abandon the craze over vitamin D.

31 jul 2022--Taking high doses of "the sunshine vitamin" doesn't reduce the risk of broken bones in generally healthy older Americans, researchers reported Wednesday.

It's the latest in a string of disappointments about a nutrient once hoped to have wide-ranging protective effects. That same study of nearly 26,000 people already had found that popping lots of vitamin D pills didn't prevent heart disease, cancer or memory loss either.

And while getting enough vitamin D is important for strong bones, "more is not better," said Dr. Meryl LeBoff of Boston's Brigham and Women's Hospital, the study's lead author.

An estimated third of Americans 60 and older take the supplements and more than 10 million blood tests for vitamin D levels are performed annually—despite years of controversy over whether the average older adult needs either.

The newest findings—added to other trials with similar results—should end that debate, wrote Drs. Steven Cummings of California Pacific Medical Center and Clifford Rosen of Maine Medical Center Research Institute in a commentary in the medical journal.

"People should stop taking vitamin D supplements to prevent major diseases"—and doctors should stop the routine screenings that fuel concern, the pair concluded. They weren't involved in the latest study.

Just how much vitamin D should people get? The U.S. recommends 600 to 800 international units a day to ensure that everyone, young and old, gets enough. While our skin makes vitamin D from sun exposure, that can be tougher in winter. Milk and certain other foods are fortified with the nutrient to help.

The bigger question was whether more than that recommended amount might be better, to prevent fractures or maybe other disorders, too. To address conflicting scientific reports, Brigham and Woman's preventive medicine chief Dr. JoAnn Manson started the largest study of its type to track a variety of health outcomes in nearly 26,000 generally healthy Americans in their 50s or older. The latest results compare bone fractures in those who took either a high dose—2,000 international units of the most active form of vitamin D, called D-3—or dummy pills every day for five years.

The supplements didn't reduce the risk of broken hips or other bones, LeBoff reported in the New England Journal of Medicine. While vitamin D and calcium work best together, she said even the 20% of study participants who also took a calcium supplement didn't benefit. Nor did the small number of study participants who had low blood levels of vitamin D.

Still, LeBoff cautioned that the study didn't include people who may require supplements because of bone-thinning osteoporosis or other disorders, or those with severe vitamin D deficiencies. And Manson said more research is needed to tell if there are additional high-risk groups who might benefit.

Overall, "these findings overturn dogma and cast doubt on the value of routine screening for vitamin D blood levels and blanket recommendations for supplementation," Manson said. "Spending time outdoors, being physically active and having a heart-healthy diet will lead to greater gains in health" for most people.

More information: Supplemental Vitamin D and Incident Fractures in Midlife and Older Adults, New England Journal of Medicine (2022). DOI: 10.1056/NEJMoa2202106

Journal information: New England Journal of Medicine 

 

Five years of high-dose vitamin D did not affect incidence of cardiovascular disease or cancer

by University of Eastern Finland

Credit: CC0 Public Domain

A trial by the University of Eastern Finland found that taking a much higher dose of vitamin D than recommended for five years did not affect total mortality or the incidence of cardiovascular disease or cancer in older men and women.

29 jan 20222--In population studies, low levels of vitamin D in the body have been linked to an increased risk of many chronic diseases as well as premature death. However, it cannot be directly deduced from such observational studies whether the use of vitamin D supplementation can reduce the risk of disease or death. The early 2010s saw the commencement of large-scale vitamin D trials in several countries examining the effects of higher than recommended doses of vitamin D on the risk of developing diseases. One of these was the Finnish Vitamin D Trial (FIND) conducted at the University of Eastern Finland in 2012–2018.

In the FIND trial, 2,495 participants (men 60 years or older and women 65 years or older) were randomized for five years to either the placebo group or the groups that received either 40 or 80 micrograms (1600 or 3200 IU) of vitamin D3 per day. All participants were free of cardiovascular disease and cancer at the start of the trial and were allowed to use their own vitamin D supplement of up to 20 micrograms (800 IU) per day (the recommended intake for this age group at the time when the trial was started). At the beginning and during the trial, research forms were used to collect comprehensive information from the subjects on lifestyle, nutrition, risk factors for and the incidence of diseases. Information on the incidence of diseases and on deaths was also obtained from national health registers. Approximately one fifth of the randomly selected subjects underwent more detailed examinations and provided blood samples.

Majority were not deficient in vitamin D at the start of the trial

During the five years of the trial, 119 participants developed cardiovascular disease, 129 subjects were diagnosed with cancer and 19 died. There was no statistically significant difference in the number of events between the groups. The vitamin D doses proved to be safe as no differences in side effects were observed between the groups. In the sub-sample examined in more detail, the mean blood vitamin D (calcidiol) concentration, was 75 nmol/L (30 ng/mL) at baseline. After one year, the mean calcidiol concentration was 100 nmol/L (40 ng/mL) in the group taking 40 micrograms of vitamin D per day and 120 nmol/L (48 ng/mL) in the group taking 80 micrograms of vitamin D per day. There was no significant change in the calcidiol concentrations in the placebo group. Only 9% of subjects had low vitamin D levels at baseline, i.e. they had a blood calcidiol concentration of less than 50 nmol/L (20 ng/mL).

The findings of the FIND trial are well in line with other similar studies that have shown that taking higher doses of vitamin D than recommended for many years does not have a significant effect on the risk of developing cardiovascular disease or cancer if the body's vitamin D status is already adequate. In Finland, the average vitamin D intake of the population has increased since the early 2000s due to, among other things, the vitamin D supplementation of vegetable oil spreads and liquid dairy products as well as the increased use of vitamin D supplements. Securing one's vitamin D intake with vitamin D supplements is still recommended, especially during the winter, if the diet is low in sources of vitamin D, such as fish or vitamin D-fortified foods. In Finland, vitamin D supplementation of 10 micrograms per day (400 IU) is recommended for the adult population; the recommendation is 20 micrograms per day (800 IU) for those aged 75 and over. However, the study does not support the use of large vitamin D doses for prevention of cardiovascular diseases or cancer.

In addition to these main findings, the FIND trial will provide comprehensive reports on the effects of vitamin D supplementation on, among other things, type 2 diabetes, fractures and falls, mood changes, infections, pain conditions, and other outcomes.

More information: Jyrki K Virtanen et al, Vitamin D supplementation and prevention of cardiovascular disease and cancer in the Finnish Vitamin D Trial—a randomized controlled trial, The American Journal of Clinical Nutrition (2021). DOI: 10.1093/ajcn/nqab419

Vitamin D appears to play role in COVID-19 mortality rates

by Amanda Morris, Northwestern University

Credit: CC0 Public Domain

After studying global data from the novel coronavirus (COVID-19) pandemic, researchers have discovered a strong correlation between severe vitamin D deficiency and mortality rates.

10 may 2020--Led by Northwestern University, the research team conducted a statistical analysis of data from hospitals and clinics across China, France, Germany, Italy, Iran, South Korea, Spain, Switzerland, the United Kingdom (UK) and the United States.

The researchers noted that patients from countries with high COVID-19 mortality rates, such as Italy, Spain and the UK, had lower levels of vitamin D compared to patients in countries that were not as severely affected.

This does not mean that everyone—especially those without a known deficiency—needs to start hoarding supplements, the researchers caution.

"While I think it is important for people to know that vitamin D deficiency might play a role in mortality, we don't need to push vitamin D on everybody," said Northwestern's Vadim Backman, who led the research. "This needs further study, and I hope our work will stimulate interest in this area. The data also may illuminate the mechanism of mortality, which, if proven, could lead to new therapeutic targets."

The research is available on medRxiv, a preprint server for health sciences.

Backman is the Walter Dill Scott Professor of Biomedical Engineering at Northwestern's McCormick School of Engineering. Ali Daneshkhah, a postdoctoral research associate in Backman's laboratory, is the paper's first author.

Backman and his team were inspired to examine vitamin D levels after noticing unexplained differences in COVID-19 mortality rates from country to country. Some people hypothesized that differences in healthcare quality, age distributions in population, testing rates or different strains of the coronavirus might be responsible. But Backman remained skeptical.

"None of these factors appears to play a significant role," Backman said. "The healthcare system in northern Italy is one of the best in the world. Differences in mortality exist even if one looks across the same age group. And, while the restrictions on testing do indeed vary, the disparities in mortality still exist even when we looked at countries or populations for which similar testing rates apply."Instead, we saw a significant correlation with vitamin D deficiency," he said.

By analyzing publicly available patient data from around the globe, Backman and his team discovered a strong correlation between vitamin D levels and cytokine storm—a hyperinflammatory condition caused by an overactive immune system—as well as a correlation between vitamin D deficiency and mortality.

"Cytokine storm can severely damage lungs and lead to acute respiratory distress syndrome and death in patients," Daneshkhah said. "This is what seems to kill a majority of COVID-19 patients, not the destruction of the lungs by the virus itself. It is the complications from the misdirected fire from the immune system."

This is exactly where Backman believes vitamin D plays a major role. Not only does vitamin D enhance our innate immune systems, it also prevents our immune systems from becoming dangerously overactive. This means that having healthy levels of vitamin D could protect patients against severe complications, including death, from COVID-19.

"Our analysis shows that it might be as high as cutting the mortality rate in half," Backman said. "It will not prevent a patient from contracting the virus, but it may reduce complications and prevent death in those who are infected."

Backman said this correlation might help explain the many mysteries surrounding COVID-19, such as why children are less likely to die. Children do not yet have a fully developed acquired immune system, which is the immune system's second line of defense and more likely to overreact.

"Children primarily rely on their innate immune system," Backman said. "This may explain why their mortality rate is lower."

Backman is careful to note that people should not take excessive doses of vitamin D, which might come with negative side effects. He said the subject needs much more research to know how vitamin D could be used most effectively to protect against COVID-19 complications.

"It is hard to say which dose is most beneficial for COVID-19," Backman said. "However, it is clear that vitamin D deficiency is harmful, and it can be easily addressed with appropriate supplementation. This might be another key to helping protect vulnerable populations, such as African-American and elderly patients, who have a prevalence of vitamin D deficiency."

More information: Ali Daneshkhah et al. The Possible Role of Vitamin D in Suppressing Cytokine Storm and Associated Mortality in COVID-19 Patients, MEDRXIV (2020). DOI: 10.1101/2020.04.08.20058578

Vitamin D could help fight off COVID-19

by Catherine O'mahony, Trinity College Dublin

Credit: CC0 Public Domain

Researchers from The Irish Longitudinal Study on Ageing (TILDA) at Trinity College Dublin have released a crucial report today in response to the COVID-19 pandemic.

07 april 2020--The report, "Vitamin D deficiency in Ireland—implications for COVID-19. Results from the Irish Longitudinal Study on Ageing (TILDA)," finds that Vitamin D plays a critical role in preventing respiratory infections, reducing antibiotic use, and boosting the immune system response to infections.

With one in eight Irish adults under 50 deficient in Vitamin D, the report highlights the importance of increasing intake.

How is Vitamin D produced?

Vitamin D is produced in the skin by exposing the body to just 10-15 minutes per day of sun. In Ireland Vitamin D can only be made between late March and late September. It cannot be made in winter, and the amount that we make in summer depends on how much sun we get, weather and other factors. Even in summer, getting a sufficient amount of Vitamin D can pose a challenge due to cloud cover, rainy weather and a lack of sunshine.

The good news is that deficiency can be remedied by adequate intake of foods and by supplementation. Vitamin D is readily found in foods like eggs, liver and oily fish—such as salmon or mackerel—as well as fortified foods such as cereals and dairy products.

Is the Irish population getting enough?

TILDA researchers have found there is insufficient daily intake of the vitamin across Ireland.

Some of TILDA's key findings are:

• 47% of all adults over 85 are deficient in winter
• 27% of adults over 70 who are 'cocooning' are estimated to be deficient
• 1 in 8 adults over 50 are deficient all year round
• Only 4% of men and 15% of women take a Vitamin D supplement

Who is most at risk of Vitamin D deficiency?

People who get little sun exposure or eat inadequate amounts of fortified foods are most at risk, especially those who are currently house-bound or confined to their homes. Other people who fall into the high-risk category are those who are obese or physically inactive, and those that have asthma or chronic lung disease.

Vitamin D is available without prescription. What is needed now is for people to increase their Vitamin D intake, especially as supplementation is low across the nation, and particularly low in men.

What is the recommended intake for Vitamin D?

TILDA researchers recommend that adults over 50 should take supplements—not just in winter, but all year round if they don't get enough sun. Those who are 'cocooning' at present should also take supplements.

Professor Rose Anne Kenny, principal investigator of TILDA, said: '"We have evidence to support a role for Vitamin D in the prevention of chest infections, particularly in older adults who have low levels. In one study Vitamin D reduced the risk of chest infections to half in people who took supplements. Though we do not know specifically of the role of Vitamin D in COVID infections, given its wider implications for improving immune responses and clear evidence for bone and muscle health, those cocooning and other at-risk cohorts should ensure they have an adequate intake of Vitamin D. Cocooning is a necessity but will reduce physical activity. Muscle deconditioning occurs rapidly in these circumstances and Vitamin D will help to maintain muscle health and strength in the current crisis."

Dr. Eamon Laird, research fellow in medical gerontology and co-author of the report, said: '"These findings show our older adults have high levels of vitamin D deficiency which could have a significant negative impact on their immune response to infection. There is an even larger risk now of deficiency with those cocooning or confined indoors. However, vitamin D deficiency is not inevitable—eating foods such as oily fish, eggs, vitamin D fortified cereals or dairy products and a daily 400 IU (10ug) vitamin D supplement can help avoid deficiency. However, Ireland needs a formal vitamin D food policy/recommendation, which we are still lacking—for instance Finland has such a policy and has virtually eliminated deficiency in their population."

More information: Vitamin D deficiency in Ireland—implications for COVID-19. Results from the Irish Longitudinal Study on Ageing (TILDA). tilda.tcd.ie/publications/repo … _Covid19VitaminD.pdf

Provided by Trinity College Dublin 

New study reveals a strong link between vitamin D deficiency and increased mortality, especially diabetes-related deaths

by Diabetologia

Credit: CC0 Public Domain

New research presented at this year's Annual Meeting of the European Association for the Study of Diabetes (EASD) in Barcelona, Spain (16-20 Sept) reveals that vitamin D deficiency is strongly linked to increased mortality, especially in younger and middle-aged people, and is particularly associated with diabetes-related deaths.

20 sept 2019--The research was conducted by Dr. Rodrig Marculescu and colleagues at the Medical University of Vienna, Austria. It analysed the effects of low 25-hydroxyvitamin D (25D) (referred to as vitamin D) levels in the blood on overall and cause-specific mortality in a large study cohort covering all age groups, and taken from a population with minimal vitamin D supplementation in old age.

Vitamin D deficiency is a widely prevalent and easily correctable risk factor for early death, and evidence for its link to mortality comes from numerous studies and clinical trials. The majority of this research to date has however come from looking at older populations, and the authors believe that many of the largest scale studies may have been affected by increased rates of vitamin D supplementation in old age. They also note: "Cause-specific mortalities and the impact of age on the association of vitamin D with the risk of death have not yet been reported in detail."

The researchers took their data from the records of all 78,581 patients (mean age 51.0 years, 31.5% male) who had a vitamin D (25D) measurement taken at the Department of Laboratory Medicine, General Hospital of Vienna between 1991 and 2011, which was then matched with the Austrian national register of deaths. The first 3 years of mortality following the vitamin D measurement were excluded from the analysis, and patients were followed for up to 20 years where possible, with a median follow-up of 10.5 years.

The authors used a blood level of vitamin D 50 nmol/L, a commonly used cut-off value for vitamin D deficiency, as their reference value to which other levels would be compared, and set their low and high levels for which risk would be calculated at 10 nmol/L and 90 nmol/L respectively.

The study found that vitamin D levels of 10 nmol/L or less were associated with a 2-3 fold increase in risk of death, with the largest effect being observed in patients aged 45 to 60 years (2.9 times increased risk). Levels of 90 nmol/L or greater were associated with a reduction in all-cause mortality of 30-40%, again with the largest effect being found in the 45 to 60-years-old age group (a 40% reduction in risk). No statistically significant associations between vitamin D levels and mortality were observed in patients over the age of 75

With regard to cause-specific mortality, the authors were surprised to find the strongest associations of vitamin D were with causes of death other than cardiovascular disease and cancer. Differences between the age groups were even more pronounced for these causes of death and, again, the largest effect was found in patients aged 45 to 60 years. Further subdivision of these non-cardiovascular, non-cancer causes of death revealed the largest effect of vitamin for diabetes with a 4.4 times higher risk of death from the disease in the vitamin D deficient group (less than or equal to 50 nmol/L) than for study participants whose serum vitamin D was above 50 nmol/L.

Plotting the risk of death according to vitamin D level in the various subgroups did not support a risk resurgence at higher vitamin D levels above 100 nmol/L. The authors say this further diminishes concerns about a possible negative effect of vitamin D in the higher concentration range, as have been shown in some previous studies reporting "inverse J-shaped" risk association (meaning risk decreased to a certain level of vitamin D and then started increasing again at higher levels).

The team conclude: "Our survival data from a large cohort, covering all age groups, from a population with minimal vitamin D supplementation at old age, confirm a strong association of vitamin D deficiency (under 50 nmol/L) with increased mortality. This association is most pronounced in the younger and middle-aged groups and for causes of deaths other than cancer and cardiovascular disease, especially diabetes."

The researchers go on to suggest that: "Our findings strengthen the rationale for widespread vitamin D supplementation to prevent premature mortality, emphasize the need for it early in life and mitigate concerns about a possible negative effect at higher levels."

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Big studies give mixed news on fish oil, vitamin D

Although fish oil taken by healthy people, at a dose found in many supplements, showed no clear ability to lower heart or cancer risks, higher amounts of a purified, prescription fish oil, such as Vascepa, slashed heart problems and heart-related deaths among people with high triglycerides, a type of fat in the blood, and other risks for heart disease.

11 nov 2018--Taking fish oil or vitamin D? Big studies give long-awaited answers on who does and does not benefit from these popular nutrients.
Fish oil taken by healthy people, at a dose found in many supplements, showed no clear ability to lower heart or cancer risks. Same for vitamin D.
But higher amounts of a purified, prescription fish oil slashed heart problems and heart-related deaths among people with high triglycerides, a type of fat in the blood, and other risks for heart disease. Doctors cheered the results and said they could suggest a new treatment option for hundreds of thousands of patients like these.
Up to 10 percent of U.S. adults take fish oil . Even more take vitamin D , despite no major studies to support the many health claims made for it.
"Those who peddle it promote it as good for everything," but in this definitive test, vitamin D "showed a big nothing," said Dr. James Stein, a heart specialist at the University of Wisconsin-Madison. He had no role in the studies or ties to the companies involved.
Results were revealed Saturday at an American Heart Association conference in Chicago and published by the New England Journal of Medicine.

ABOUT FISH OIL

These oils, also called omega-3 fatty acids, are found in salmon, tuna and certain other fish. They reduce triglycerides and inflammation and may have other effects . There are different types, including EPA and DHA.
One study tested 4 grams a day of Amarin Corp.'s prescription Vascepa, which is concentrated EPA, in more than 8,000 patients with high triglycerides and a greater risk of heart problems for various reasons. All were already taking a statin such as Lipitor or Zocor to lower cholesterol. Half were given Vascepa and the rest, mineral oil capsules as a comparison.
After five years, about 17 percent of those on Vascepa had suffered one of these problems—a heart attack, stroke, heart-related death or clogged arteries requiring medical care—versus 22 percent of the others.
That worked out to a 25 percent reduction in risk. Looked at individually, heart attacks, heart-related deaths and strokes all were lower with Vascepa. Only 21 people would need to take Vascepa for five years to prevent one of the main problems studied—favorable odds, Stein said.
Side effects may be a concern: More people on Vascepa were hospitalized for an irregular heartbeat—3 percent versus 2 percent of the comparison group. Doctors say that's puzzling because other research suggests fish oil lowers that risk.
The concern with the heart rhythm problem is that it can raise the risk of stroke, but there were fewer strokes among those on Vascepa, said study leader Dr. Deepak Bhatt of Brigham and Women's Hospital in Boston.
Vascepa costs around $280 a month; many insurers cover it. Amarin sponsored the study and some study leaders work or consult for the company.

A BROADER TEST

The other study tested a lower 1 gram daily dose of a different type of fish oil—an EPA/DHA combo sold as Lovaza or Omacor and in generic form—in 26,000 people with no prior heart problems or cancer.
After about five years, rates of a combined measure of heart attacks, strokes and other problems were similar for fish oil users and a comparison group. Cancer rates and deaths also were similar.

There were fewer heart attacks in the fish oil group—145 versus 200 in the comparison group. The study leader, Dr. JoAnn Manson at Brigham and Women's, called that "a substantial benefit," but several independent experts disagreed because of the way the study was set up to track this and certain other results.
"These findings are speculative and would need to be confirmed in a separate trial," said the Cleveland Clinic's Dr. Steven Nissen.

FISHY COMPARISONS?

Both studies share a problem: the oils used for the comparison groups, which may not have been true placebos. The Vascepa study used mineral oil, which interferes with statin drugs, raises cholesterol, and might have made the comparison group fare worse and made Vascepa look better than it truly was.
The other study used olive oil, which might have helped that comparison group do better, possibly masking any benefit to the others from fish oil.
Leaders of both studies say any effect from the comparison oils isn't enough to alter the main results, and independent experts agreed. But Nissen, who is leading another fish oil study, is using corn oil as a comparison.

THE 'SUNSHINE' VITAMIN

Manson's study also tested vitamin D, which the skin makes from sun exposure. It's tough to get enough from foods like milk, eggs and oily fish, though many foods now are fortified with it. Some studies have found that people with lower levels of D are more likely to develop cancer, but it's not known if supplements alter that risk.
Study participants took 2,000 international units of D-3 (the most active form of vitamin D, also called cholecalciferol) or fake vitamin pills for five years.
Vitamin D did not affect the odds of having a heart attack or stroke or developing cancer. After excluding the first two years of use, researchers saw fewer cancer deaths among those on the vitamin—112 versus 149 in the placebo group.
"Cancer can take years to develop" so a difference may not show up right away, Manson said. "This looks promising" and people will be studied longer to see if the trend holds up, she said.
Several other experts said these numbers just hint at a possible benefit that needs more study.
"These 'positive' results need to be interpreted with caution," Dr. Clifford Rosen of Maine Medical Center Research Institute and Dr. John Keaney Jr. of the University of Massachusetts wrote in a commentary in the medical journal.

Do you take calcium and vitamin D to protect your bones? A new study says it doesn't help

If taking more vitamin and mineral supplements is part of your plan for a healthier new year, a new study may prompt you to reconsider.
Researchers who scoured the medical literature for evidence that calcium and vitamin D pills could help prevent bone fractures came up empty.

04 JAN 2018--Their analysis focused on adults older than age 50 who lived on their own (that is, not in a nursing home or other type of residential care facility). Fractures are a serious health concern for this population—previous studies have found that about 40 percent of women in this age group will wind up with at least one "major osteoporotic fracture" at some point in their lives, and that among adults who break a hip, 20 percent died within a year of their injury.
The researchers, led by Dr. Jia-Guo Zhao of Tianjin Hospital in northeastern China, combed through clinical trials, systematic reviews and other reports published in the last decade, since late 2006. They identified 51,145 people who were included in studies assessing the role of calcium and/or vitamin D in preventing bone fractures.
Their findings appear in Tuesday's edition of the Journal of the American Medical Association.
Among the 14 trials that pitted calcium supplements against either a placebo or no treatment, there was no statistically significant relationship between use of the mineral (in pill form) and the risk of suffering a hip fracture. Nor was there any clear link between calcium supplements and fractures involving the spine or other bones.
Even when the researchers accounted for each study participant's gender, past history of bone fractures, the amount of calcium they consumed in their diets and the dose of the calcium pills they took (if they did), there was still no sign that supplements were helpful.
An additional 17 trials examined the role of vitamin D, which helps the body absorb calcium. Once again, they found no statistically significant link between supplement use and hip fracture risk. Ditto for fractures in the spine and elsewhere.
Upon drilling down to certain subgroups, they found that for people who started out with at least 20 nanograms of vitamin D per milliliter of blood, adding more vitamin D through supplements was associated with a greater risk of hip fractures. The same was true for people who took high doses of vitamin D supplements just once a year.
Finally, there were 13 trials involving people who took a combined calcium-vitamin D supplement. As before, there was no statistically significant link between supplement use and the risk for any kind of fracture or combination of fractures. That held up even when accounting for gender, past fractures, supplement dose, dietary calcium or baseline blood levels of vitamin D.
The researchers noted that thousands of people in this final group were participants in the Women's Health Initiative, a long-term study sponsored by the National Heart, Lung and Blood Institute in the U.S. Earlier reports based on data gathered by the Women's Health Initiative found that calcium and vitamin D supplements were associated with a lower risk of fractures, but only for women who took hormone therapy after menopause. To get a clearer picture of the direct link (if any) between supplements and fracture risk, Zhao and his colleagues opted not to include data from women on hormone therapy.
It's still possible that calcium and vitamin D supplements are useful for people who live in nursing homes or other residential facilities, the study authors wrote. Such people are more likely to have osteoporosis, due to a combination of poor diet, less sun exposure (which the body needs to synthesize vitamin D) and other factors.
But for older adults who live on their own, they wrote, the results are clear: "These findings do not support the routine use of these supplements."

More information: Jia-Guo Zhao et al. Association Between Calcium or Vitamin D Supplementation and Fracture Incidence in Community-Dwelling Older Adults, JAMA (2017). DOI: 10.1001/jama.2017.19344

Worldwide health authorities urged to rethink vitamin D guidelines

Worldwide health authorities are being urged to rethink official guidance around vitamin D following the publication of a ground breaking study from the University of Surrey, which dispels the myth that vitamin D2 and D3 have the same nutritional value.

03 aug 2017--In the first ever study of its kind, using low doses of vitamin D in fortified food, researchers from the University of Surrey investigated which of the two types of vitamin D, D2 or D3, was more effective in raising levels of this vital nutrient in the body. Vitamin D3 is derived from animal products, while D2 is plant-based.
Researchers examined the vitamin D levels of 335 South Asian and white European women over two consecutive winter periods, a time when the nutrient is known to be lacking in the body. The women were split into five groups, with each group receiving either a placebo, a juice containing vitamin D2 or D3 and a biscuit with D2 or D3.
They found that vitamin D3 was twice as effective in raising levels of the vitamin in the body than its counterpart D2. Vitamin D levels in women who received vitamin D3 via juice or a biscuit increased by 75 per cent and 74 per cent respectively compared to those who were given D2 through the same methods. Those given D2 saw an increase of 33 per cent and 34 per cent over the course of the 12-week intervention.
The research also found that nutrient levels of both vitamin D2 and D3 rose as a result of both food and acidic beverages such as juice, which were found to be equally as effective.
Those who received the placebo experienced a 25 per cent reduction in the vitamin over the same period.
Current guidance given by a number of Government bodies around the world including the US National Institute of Health, state that the two forms of vitamin D are equivalent and can be used to equal effect.
Latest figures from Public Health England has found that more than 1 in 5 people in the UK have low levels of vitamin D and has increased the recommended intake of the vitamin to 10 micrograms per day, throughout the year, for everyone in the general population aged 4 years and older. Daily consumption of products containing vitamin D3 but not vitamin D2 will enable the population to meet this target helping to avoid the health implications such as osteoporosis, rickets and increased risk of cardio vascular disease which are associated with insufficient levels of vitamin D in the body.
This finding not only has implications for the health sector but also for the retail market. In recent years many retailers have added vitamin D2 to their products in the belief that it will help a person fulfil their daily intake. This study has proven that D3 is the most effective form of increasing vitamin D levels in the body.
Lead author Dr Laura Tripkovic from the University of Surrey, said: "The importance of vitamin D in our bodies is not to be underestimated, but living in the UK it is very difficult to get sufficient levels of it from its natural source, the sun, so we know it has to be supplemented through our diet.
"However, our findings show that vitamin D3 is twice as effective as D2 in raising vitamin D levels in the body, which turns current thinking about the two types of vitamin D on its head. Those who consume D3 through fish, eggs or vitamin D3 containing supplements are twice as more likely to raise their vitamin D status than when consuming vitamin D2 rich foods such as mushrooms, vitamin D2 fortified bread or vitamin D2 containing supplements, helping to improve their long term health."
Professor Susan Lanham-New, Head of the Department of Nutritional Sciences at the University of Surrey and who was Principal Investigator of the BBSRC DRINC funded trial said: "This is a very exciting discovery which will revolutionise how the healthand retail sector views vitamin D.
"Vitamin D deficiency is a serious matter, but this will help people make a more informed choice about what they can eat or drink to raise their levels through their diet."


Provided by University of Surrey

Exercise and vitamin D better together for heart health

Johns Hopkins researchers report that an analysis of survey responses and health records of more than 10,000 American adults for nearly 20 years suggests a "synergistic" link between exercise and good vitamin D levels in reducing the risk of heart attacks and strokes.

01 may 2017--Both exercise and adequate vitamin D have long been implicated in reducing heart disease risks, but in a new study—one not designed to show cause and effect—the researchers investigated the relationship between these two health factors and their joint role in heart health. Their findings, which were published in the April 1 issue of the Journal of Clinical Endocrinology & Metabolism, identified a positive and direct relationship between exercise and vitamin D levels in the blood, which may provide evidence that exercise may boost vitamin D stores. They also found that the two factors working together seemed to somehow do more than either factor alone to protect the cardiovascular system. The researchers caution that their study is an observational one and that long-term, carefully controlled clinical trials would be needed to establish evidence for cause and effect. Nevertheless, the study does support the notion that exposure to the "sunshine" vitamin D and exercise are indicators of good health.
"In our study, both failure to meet the recommended physical activity levels and having vitamin D deficiency were very common" says Erin Michos, M.D., M.H.S., associate director of preventive cardiology and associate professor of medicine at the Ciccarone Center for the Prevention of Heart Disease at the Johns Hopkins University School of Medicine. "The bottom line is we need to encourage people to move more in the name of heart health." Michos adds that exposure to a few minutes a day of sunlight in non-winter seasons, eating a well-balanced meal that includes oily fish such as salmon, along with fortified foods like cereal and milk, may be enough to provide adequate levels of vitamin D for most adults.
For their data analysis, the Johns Hopkins researchers used previously gathered information from the federally funded Atherosclerosis Risk in Communities study beginning in 1987 and collected from 10,342 participants initially free of heart or vascular disease. Information about participants was updated and followed until 2013, and included adults from Forsyth County, North Carolina; Jackson, Mississippi; greater Minneapolis, Minnesota; and Washington County, Maryland. The participants were an average age of 54 at the start of the study and 57 percent were women. Twenty-one percent were African-American, with the remaining participants identifying as white.
In the first visit between 1987 and 1989, participants self-reported their exercise levels, which were compared to the American Heart Association recommendations of more than 150 minutes per week of moderate intensity exercise or 75 minutes per week or more of vigorous intensity. The researchers used the information to classify each participant's exercise level as adequate, intermediate or poor. People with adequate exercise levels met the AHA's recommendations, those with intermediate levels exercised vigorously for up to 74 minutes per week or exercised moderately for less than 149 minutes a week, and those classified as poor didn't exercise at all. About 60 percent of the participants had inadequate exercise in the poor or intermediate categories. The researchers converted the exercise to metabolic equivalent tasks (METs), an exercise intensity scale used by cardiologists and other clinicians to assess fitness. They then calculated physical activity levels by multiplying METs by minutes per week of exercise.
Reviewing data from the second study visit by each participant between 1990 and 1992, the researchers measured vitamin D levels in the blood by detecting the amount of 25-hydroxyvitamin D. Anyone with less than 20 nanograms per milliliter of 25-hydroxyvitamin D was considered deficient for vitamin D, and levels above 20 nanograms per milliliter were considered adequate. Thirty percent of participants had inadequate vitamin D levels.
In the first part of their study, the Johns Hopkins team showed that exercise levels positively corresponded to vitamin D levels in a direct relationship, meaning that the more one exercised, the higher their vitamin D levels seemed. For example, people with adequate exercise had an average 25-hydroxyvitamin D level of 26.6 nanograms per milliliter, those with intermediate exercise had 24.4 nanograms per milliliter, and those with poor exercise had 22.7 nanograms per milliliter. Those meeting recommended levels of exercise at visit 1 had a 31 percent lower risk of being vitamin D deficient at visit 2. Yet, the researchers only saw such a positive relationship between exercise and vitamin D in whites and not African-Americans.
In the next part of the study, they found that the most active participants with the highest vitamin D levels had the lowest risk for future cardiovascular disease. Over the 19 years of the study, 1800 adverse cardiac events occurred, including heart attack, stroke or death due to heart disease or stroke. After adjusting the data for age, sex, race, education, smoking, alcohol use, blood pressure, diabetes, high blood pressure medication, cholesterol levels, statin use and body mass index, the researchers found that those people who met both the recommended activity levels and had vitamin D levels above 20 nanograms per milliliter experienced about a 23 percent less chance of having an adverse cardiovascular event than those people with poor physical activity who were deficient for vitamin D. On the other hand, people who had adequate exercise but were vitamin D deficient didn't have a reduced risk of an adverse event. In other words, the combined benefit of having adequate vitamin D and exercise levels was better than either health factor alone.
But Michos says that sun exposure may not be the whole story of the direct relationship found between exercise and vitamin D levels, since vitamin D produced by the skin after exposure to sunlight tends to level off when the body makes enough, and the levels in these participants didn't show signs of doing so. She says this points to evidence that there may be something else going on in the body that causes vitamin D and exercise to positively influence levels of each other. For example, people who exercise may also have other healthy habits that influence vitamin D levels such as lower body fat and a healthier diet. Alternatively, people who exercise may take more vitamin supplements.
As for the racial disparity they saw, this could mean promoting physical activity may not be as effective for raising vitamin D levels in African-Americans as in whites. Michos notes that people with darker skin produce vitamin D less efficiently after sun exposure, possibly due to the greater amount of melanin pigment, which acts as a natural sunscreen. African-Americans also tend to have lower levels of 25-hydroxyvitamin D overall but they don't seem to experience the same consequences, such as bone fractures, that whites have with similarly low levels.
Michos cautions that people who meet the recommended daily amount of 600 to 800 International Units a day and who have adequate levels of vitamin D don't need to take additional vitamin supplements. "More isn't necessarily better once your blood levels are above 20 nanograms per milliliter," says Michos. "People at risk of bone diseases, have seasonal depression, or are obese should have their physicians measure vitamin D levels to ensure they're adequate, but for many, the best way to ensure adequate blood levels of the vitamin is from sun exposure, healthy diet, being active and maintaining a normal body weight." She adds, "Just 15 minutes of sunlight in the summer produces about 3000 international units of vitamin D depending on latitude and skin pigmentation, which is equivalent to 30 glasses of milk. Just be sure to use sunscreen if you plan to be outside longer than 15 minutes."
While the health boost from regular physical activity is undisputed, the benefits of vitamin D supplements haven't yet been proven for heart health. Michos notes that a recent randomized clinical trial published in JAMA Cardiology failed to show any cardiovascular benefit with high-doses of monthly vitamin D supplements among participants living in New Zealand. She says that larger studies including more diverse populations of patients and different dosing regimens are currently on-going and, when published, will provide further insight and guide recommendations for patients.

More information: Kathleen Chin et al, Physical Activity, Vitamin D, and Incident Atherosclerotic Cardiovascular Disease in Whites and Blacks: The ARIC Study, The Journal of Clinical Endocrinology & Metabolism (2017). DOI: 10.1210/jc.2016-3743


Provided by Johns Hopkins University School of Medicine

Increased levels of active vitamin D can help to optimize muscle strength

Researchers at the University of Birmingham have shown that increasing the levels of active vitamin D can help to optimise muscle strength in humans.
The team hope that the findings will inform the design of future supplementation studies, and begin to answer questions as to the optimal levels of vitamin D required for healthy muscles.

28 feb 2017--The study, published in PLOS ONE, builds on previous knowledge showing levels of inactive vitamin D to be associated with a lack of muscle mass.
The research is the result of a cutting edge technique that allowed both active and inactive forms of vitamin D to be assessed alongside their impact on various muscle functions.
Dr Zaki Hassan-Smith, from the University of Birmingham, explained, "We have a good understanding of how vitamin D helps bone strength, but we still need to learn more about how it works for muscles. When you look at significant challenges facing healthcare providers across the world, such as obesity and an ageing population, you can see how optimising muscle function is of great interest."
"Previous studies have tested for the inactive forms of vitamin D in the bloodstream, to measure vitamin D deficiency. Here, we were able to develop a new method of assessing multiple forms of vitamin D, alongside extensive testing of body composition, muscle function and muscle gene expression."
116 healthy volunteers, aged between 20-74, were recruited to the trial. Participants had both active and inactive levels of vitamin D measured alongside physical characteristics including body fat and 'lean mass', a measure of muscle bulk.
Women with a healthy body composition, and lower body fat, were less likely to have high levels of inactive vitamin D, a marker of vitamin D deficiency. This was echoed by the finding that levels of inactive vitamin D were lower in women with increased body fat. This would suggest a relationship between vitamin D and body composition.
However, the active form of vitamin D was not associated with body fat, but was associated with lean mass.
Individuals with an increased lean mass, and muscle bulk, had a higher level of active vitamin D in the bloodstream.
Dr Hassan Smith added, "By looking at multiple forms in the same study, we can say that it is a more complex relationship that previously thought. It may be that body fat is linked to increased levels of inactive vitamin D, but lean mass is the key for elevated levels of active vitamin D. It is vital to understand the complete picture, and the causal mechanisms at work, so we can learn how to supplement vitamin D intake to enhance muscle strength."
In this study some of the positive associations between active vitamin D and muscle bulk were not seen in men.
Future studies with larger cohorts will help to identify if this is due to biological differences. The team will now work alongside international collaborators to further investigate the mechanisms at work through lab-based studies and clinical trials.

More information: PLOS ONE, DOI: 10.1371/journal.pone.0170665


Provided by University of Birmingham

Vitamin D protects against colds and flu, finds major global study

Credit: CC0 Public Domain

Vitamin D supplements protect against acute respiratory infections including colds and flu, according to a study led by Queen Mary University of London (QMUL).

17 feb 2017--The study provides the most robust evidence yet that vitamin D has benefits beyond bone and muscle health, and could have major implications for public health policy, including the fortification of foods with vitamin D to tackle high levels of deficiency in the UK.
The results, published in the BMJ, are based on a new analysis of raw data from around 11,000 participants in 25 clinical trials conducted in 14 countries including the UK, USA, Japan, India, Afghanistan, Belgium, Italy, Australia and Canada. Individually, these trials yielded conflicting results, with some reporting that vitamin D protected against respiratory infections, and others showing no effect.
Lead researcher Professor Adrian Martineau from QMUL said: "This major collaborative research effort has yielded the first definitive evidence that vitamin D really does protect against respiratory infections. Our analysis of pooled raw data from each of the 10,933 trial participants allowed us to address the thorny question of why vitamin D 'worked' in some trials, but not in others.
"The bottom line is that the protective effects of vitamin D supplementation are strongest in those who have the lowest vitamin D levels, and when supplementation is given daily or weekly rather than in more widely spaced doses.
"Vitamin D fortification of foods provides a steady, low-level intake of vitamin D that has virtually eliminated profound vitamin D deficiency in several countries. By demonstrating this new benefit of vitamin D, our study strengthens the case for introducing food fortification to improve vitamin D levels in countries such as the UK where profound vitamin D deficiency is common."
Vitamin D - the 'sunshine vitamin' - is thought to protect against respiratory infections by boosting levels of antimicrobial peptides - natural antibiotic-like substances - in the lungs. Results of the study fit with the observation that colds and 'flu are commonest in winter and spring, when levels of vitamin D are at their lowest. They may also explain why vitamin D protects against asthma attacks, which are commonly triggered by respiratory viruses.
Daily or weekly supplementation halved the risk of acute respiratory infection in people with the lowest baseline vitamin D levels, below 25 nanomoles per litre (nmol/L). However, people with higher baseline vitamin D levels also benefited, although the effect was more modest (10 per cent risk reduction). Overall, the reduction in risk of acute respiratory infection induced by vitamin D was on a par with the protective effect of injectable 'flu vaccine against 'flu-like illnesses.
Acute respiratory infections are a major cause of global morbidity and mortality. Upper respiratory infections such as colds and 'flu are the commonest reason for GP consultations and days off work. Acute lower respiratory infections such as pneumonia are less common, but caused an estimated 2.65 million deaths worldwide in 2013. Vitamin D supplementation is safe and inexpensive, so reductions in acute respiratory infections brought about by vitamin D supplementation could be highly cost-effective.

More information: Adrian R Martineau et al, Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data, BMJ (2017).DOI: 10.1136/bmj.i6583


Provided by Queen Mary, University of London

Current evidence does not support vitamin D supplements to prevent disease

Credit: CC0 Public Domain

Current evidence does not support the use of vitamin D supplements to prevent disease, conclude researchers in The BMJ today.

24 nov 2016--Associate Professor Mark Bolland and colleagues at the University of Auckland, New Zealand and the University of Aberdeen, Scotland say those at high risk of vitamin D deficiency should be advised about sunlight exposure and diet and offered low dose supplements, but the rest of us should focus on eating a healthy balanced diet with food containing vitamin D and getting regular short bursts of sunshine.
Vitamin D is made by the skin in response to sunlight. It helps to maintain calcium levels in the body to keep bones, teeth and muscles healthy. A lack of vitamin D can lead to bone deformities such as rickets in children, and bone pain and tenderness due a condition called osteomalacia in adults.
During spring and summer, most people get enough vitamin D from sunlight on their skin and their diet. But in autumn and winter, when exposure to sunshine is minimal, the only source is from a limited range of foods such as oily fish, egg yolk, red meat, liver, fortified breakfast cereals and fat spreads.
As such, Public Health England advises that everyone should consider a 10 microgram daily vitamin D supplement of during these months.
Based on a comprehensive search of published evidence, Associate Professor Bolland and colleagues make the case that existing clinical trials show that vitamin D supplementation does not improve musculoskeletal outcomes, such as falls or fractures.
They also say there is no high quality evidence to suggest that vitamin D supplementation is beneficial for other conditions such as heart disease, stroke, and some cancers—and ongoing trial results are unlikely to alter these conclusions.
If vitamin D supplementation does have benefits, they are most likely to be seen in severely deficient vitamin D populations, they write.
In light of the uncertainty, they suggest people at high risk should be counselled about sunlight exposure and diet, and low dose vitamin D supplements considered on an individual basis. "Otherwise we conclude that current evidence does not support the use of vitamin D supplementation to prevent disease."
In a debate article also published today, two experts discuss whether healthy people should take a vitamin D supplement during the winter months.
Dr Louis Levy, head of nutrition science at Public Health England, says advice to take a vitamin D supplement of 10 micrograms a day is backed by a Scientific Advisory Committee on Nutrition (SACN) review of the evidence on musculoskeletal health outcomes.
He says "Bolland and his colleagues conclude that serum 25-hydroxyvitamin D should not fall below 25 nmol/L, just like the Scientific Advisory Committee on Nutrition did earlier this year. To achieve this, PHE advice includes getting short bursts of summer sun and a balanced diet through summer and spring. But when the days are darker and shorter and sun exposure is minimal, people should consider a daily 10 microgram vitamin D supplement, as it's difficult to get enough through diet alone."
He argues that taking 10 micrograms of vitamin D daily to prevent musculoskeletal ill health "is unlikely to result in harmful levels of vitamin D" and says getting enough vitamin D is particularly important "because poor musculoskeletal health remains in the top 10 causes of disability adjusted life years."
But Tim Spector, Professor of genetic epidemiology at King's College London, questions whether this recommendation is evidence based. He points out that, despite hundreds of studies, "highly convincing evidence of a clear role of vitamin D does not exist for any outcome."
Although vitamin D treatment still has a role in people with proved deficiency or in high risk groups, "the rest of us should avoid being 'treated' for this pseudodisease, save scarce NHS resources, and focus on having a healthy lifestyle, sunshine, and a diversity of real food."

More information: Practice: Should adults take vitamin D supplements to prevent disease? www.bmj.com/cgi/doi/10.1136/bmj.6201
Head to Head: Should healthy people take a vitamin D supplement in winter months? www.bmj.com/cgi/doi/10.1136/bmj.i6183


Provided by British Medical Journal

British scientists recommend we need to triple our daily vitamin D intake

Credit: University of Sheffield

Scientists have warned we need to triple our daily vitamin D intake to maintain healthy bones in a new report issued to the government today.
The new recommendation, made by the Science Advisory Committee on Nutrition (SACN), comes after a five year review which revealed one in five people in the UK have insufficient vitamin D levels.

30 july 2016--The human body makes most of its vitamin D from direct sunlight on the skin but we also get a small amount from some foods, including oily fish, such as salmon, eggs and foods to which vitamin D has been added, like some cereals and fat spreads.
Vitamin D is essential for the absorption of calcium– which is vital to maintain healthy bones and teeth. A lack of this vitamin can lead to a number of serious conditions including rickets in children and osteomalacia in adults, which cause bones to soften, weaken and in some cases become deformed. Other diseases such as diabetes and cancer have also been linked with low vitamin D but the evidence is still not strong.
The review, chaired by Professor Hilary Powers from the Department of Oncology and Metabolism at the University of Sheffield, concluded that in order to protect bone and muscle health, everyone over one year of age needs 10micrograms (10ug) vitamin D daily.
Groups most at risk of vitamin D deficiency include:

• People who don't spend a lot of time outdoors - such as the elderly
• Ethnic minority groups with darker skin, which doesn't make vitamin D as easily
• Those who cover their skin for religious and cultural reasons
• People in occupations with limited sunlight exposure – such as night shift workers

Professor Powers, an expert in Human Nutrition, said: "If the recommendations are followed this should reduce the risk of bone disease in the UK population.
"The review concluded that to protect bone and muscle health people should achieve a blood concentration of vitamin D of 25nmol/L all the year round.
"Until now it has been assumed that sunlight would provide the vitamin D needed by most of the population all the year round. We now know this is not true because about one in five people in the UK have a low blood level of vitamin D."
The SACN have recommended that in order to achieve this blood level people in the UK need 10ug vitamin D daily. However, the average intake of vitamin D from food and supplements is only about 3ug.
"There are very few foods that contain a good source of vitamin D so it is very important to ensure we include a variety of oily fish (such as tuna, salmon and sardines), eggs and certain fortified breakfast cereals in our diets.
"In the 1950s after World War II the government issued a dose of cod liver oil to children every day to supplement their diets with a good source of vitamin D, but it was later thought to be unnecessary."
"The government now needs to look at the evidence and recommendations in the report and consider a strategy to help people in the UK increase their vitamin D intake."


Provided by University of Sheffield

Taking vitamin D may benefit people with multiple sclerosis

Demyelination by MS. The CD68 colored tissue shows several macrophages in the area of the lesion. Original scale 1:100. Credit: Marvin 101/Wikipedia

Taking a high dose of vitamin D3 is safe for people with multiple sclerosis and may help regulate the body's hyperactive immune response, according to a pilot study published by Johns Hopkins physicians in the Dec. 30 online issue of Neurology, the medical journal of the American Academy of Neurology.

04 jan 2016--"These results are exciting, as vitamin D has the potential to be an inexpensive, safe and convenient treatment for people with MS," says study author Peter Calabresi, M.D., director of the Johns Hopkins Multiple Sclerosis Center and professor neurology at the Johns Hopkins University School of Medicine. "More research is needed to confirm these findings with larger groups of people and to help us understand the mechanisms for these effects, but the results are promising."
Low levels of vitamin D in the blood are tied to an increased risk of developing MS. People who have MS and low levels of vitamin D are more likely to have greater disability and more disease activity.
For the study, 40 people with relapsing-remitting MS received either 10,400 international units or 800 international units of vitamin D3 supplements per day for six months. Patients with severe vitamin D deficiency were not included in the study. The current recommended daily allowance of vitamin D3 is 600 international units. Blood tests at the start of the study and again at three and six months measured the amount of vitamin D in the blood and the response in the immune system's T cells, which play a key role in MS.
While researchers are still determining the optimal level of vitamin D in the blood for people with MS, a suggested range of 40 to 60 nanograms per milliliter (ng/ml) has been proposed as a target. Participants taking the high dose of vitamin D reached levels within the proposed target, whereas the group taking the low dose did not reach the target.
Side effects from the vitamin supplements were minor and were not different between the people taking the high dose and the people taking the low dose. One person in each group relapsed.
The people taking the high dose had a reduction in the percentage of inflammatory T cells related to MS severity, specifically IL-17+CD4+ and CD161+CD4+ cells. When the increase in vitamin D levels in the blood over base line levels was greater than 18 ng/ml, every additional 5 ng/ml increase in vitamin D led to a 1 percent decrease in the percentage of IL-17+CD4+ T cells in the blood. The people taking the low dose did not have any noticeable changes in the percentages of their T cell subsets.
"We hope that these changes in inflammatory T cell responses translate to a reduced severity of disease," says Calabresi. "Other clinical trials are underway to determine if that is the case."


Provided by Johns Hopkins University School of Medicine

Vitamin D pill a day may improve exercise performance and lower risk of heart disease

Taking vitamin D supplements can improve exercise performance and lower the risk of heart disease, according to the findings of a preliminary study presented today at the Society for Endocrinology annual conference in Edinburgh.

03 nov 2015--Vitamin D, which is both a vitamin and a hormone, helps control levels of calcium and phosphate in the blood and is essential for the formation of bones and teeth. Sources of Vitamin D include oily fish and eggs, but it can be difficult to get enough through diet alone. Most people generate vitamin D by exposing their skin to ultraviolet B rays in sunlight.

Previous studies suggest that vitamin D can block the action of enzyme 11-βHSD1, which is needed to make the "stress hormone" cortisol. High levels of cortisol may raise blood pressure by restricting arteries, narrowing blood vessels and stimulating the kidneys to retain water. As Vitamin D may reduce circulating levels of cortisol, it could theoretically improve exercise performance and lower cardiovascular risk factors.

In this study, researchers from Queen Margaret University in Edinburgh gave 13 healthy adults matched by age and weight 50μg of vitamin D per day or a placebo over a period of two weeks.

Adults supplementing with vitamin D had lower blood pressure compared to those given a placebo, as well as having lower levels of the stress hormone cortisol in their urine. A fitness test found that the group taking vitamin D could cycle 6.5km in 20 minutes, compared to just 5km at the start of the experiment. Despite cycling 30% further in the same time, the group taking vitamin D supplements also showed lower signs of physical exertion.

Around ten million people in England may have low vitamin D levels. On average, one in ten adults has low levels of vitamin D in summer, compared to two in five in winter. Because people with darker skin are less efficient at using sunlight to make vitamin D, up to three out of four adults with dark skin are deficient in winter.

"Our pilot study suggests that taking vitamin D supplements can improve fitness levels and lower cardiovascular risk factors such as blood pressure", said Dr Raquel Revuelta Iniesta, co-author of the study. "Our next step is to perform a larger clinical trial for a longer period of time in both healthy individuals and large groups of athletes such as cyclists or long-distance runners".

"Vitamin D deficiency is a silent syndrome linked to insulin resistance, diabetes, rheumatoid arthritis, and a higher risk for certain cancers", said lead author of the study Dr Emad Al-Dujaili. "Our study adds to the body of evidence showing the importance of tackling this widespread problem".

Provided by Society for Endocrinology