Too much of a good thing? High doses of vitamin D can lead to kidney failure

by Canadian Medical Association Journal

Credit: CC0 Public Domain

A case study in CMAJ highlights the dangers of taking too much vitamin D.

09 april 2019--A 54-year-old man, after returning from a trip to Southeast Asia where he spent much of his holiday sunbathing, showed increased levels of creatinine, suggesting kidney damage or malfunction. After referral to a kidney specialist and further testing, it was discovered that he had been prescribed high doses of vitamin D by a naturopath, who recommended a dose of 8 drops every day. Over 2 ½ years, the patient, who did not have a history of bone loss or vitamin D deficiency, took 8-12 drops of vitamin D daily, totalling 8000-12 000 IU. As a result, he had very high levels of calcium in the blood, which left him with significant kidney damage.

"Although vitamin D toxicity is rare owing to a large therapeutic range, its widespread availability in various over-the-counter formulations may pose a substantial risk to uninformed patients," writes Dr. Bourne Auguste, a Clinical Fellow in Home Dialysis at Toronto General Hospital and the University of Toronto.

The recommended daily allowance is 400-1000 IU, with 800-2000 IU recommended for adults at high-risk of osteoporosis and for older adults.

"Our experience informs us that patients and clinicians should be better informed about the risks regarding the unfettered use of vitamin D. Given new findings from the US Preventive Services Task Force, current Canadian guidelines regarding its use in low-risk individuals should be revisited," the authors suggest.

"Use of vitamin D drops leading to kidney failure in a 54-year-old man" is published April 8, 2019.

More information: CMAJ (2019). www.cmaj.ca/lookup/doi/10.1503/cmaj.180465

Provided by Canadian Medical Association Journal 

*

There's a very simple solution to your lack of vitamin D

Windows do not protect us from harmful UVA rays, but they block out beneficial UVB rays.

Windows do not protect us from harmful UVA rays, but they block out beneficial UVB rays. Credit: Bearfaced

Despite living in a famously sunny country, we've been getting reports of widespread vitamin D deficiency for some time now. The solution to this problem is simply the judicious use of a plentiful, if somewhat maligned, natural resource.

06 july 2013--As an ardent Beatles fan, I became aware of the lesser-known fact that John Lennon and Paul McCartney used to sunbathe in Liverpool's Strawberry Fields cemetery. This behaviour probably seems extraordinary for people in present day Australia where we're used to being lectured about the importance of protecting ourselves from the sun.

I also knew that old family friends who grew up in England after the Second World War were forced to swallow cod liver oil. This is also unusual today; some of us do dole out fish-oil tablets in the morning, but usually because of dubious advertising claims that they'll enhance our childrens' performance on school tests.

These otherwise seemingly disconnected post-war temperate zone activities (sunbathing and consuming cod liver oil) are linked by their capacity to supply people with vitamin D3 (cholecalciferol). Around 90% of our vitamin D3 is produced in the skin by ultraviolet irradiation B (UVB) of its precursor 7-dehydrocholesterol.

Between 10,000 and 20,000 international units (IU) of vitamin D3 can be made by direct exposure of large areas of human skin (such as your tummy, back or legs) to UVB in the middle of the day (when UV index is greater than three).

Vitamin D3 is also found in oily fish and cod liver oil, but the capsules commonly taken as supplements contain only about 1,000 IU each. The body self-regulates production of vitamin D, some is stored in fat and you cannot produce too much.

Low vitamin D epidemic

Australia is facing an epidemic of vitamin D deficiency, with as much as a third of the population having less than recommended levels. Even people such as gardeners, who are outside all day but lathered in sunscreens and wearing long-sleeved shirts and broad hats have chronically low vitamin D3 levels.

Vitamin D is important for maintaining calcium and phosphate levels for bone formation, and allowing proper functioning of parathyroid hormone. Low levels of this hormone can produce fatigue, muscle pain and weakness, weight gain, poor sleep and concentration and bone diseases.

Low vitamin D levels have been implicated in forms of cancer, high-blood pressure and autoimmune disease, such as multiple sclerosis. Indeed, multiple sclerosis is an interesting example here.

It has long been known that the incidence of multiple sclerosis is much lower at the equator than in temperate zones. Many have wondered whether the difference can be explained by the higher levels of UVB and light clothing worn at the equator that combine to elevate vitamin D3 levels.

The overall health impact of even mild vitamin D deficiency is unlikely to be positive, so this is not an issue we can afford to ignore. It just so happens that Australian health professionals are already raising awareness of the problem.

Sun phobia and low vitamin D

There is such a fear of skin cancer in Australia that many health professionals are reluctant to recommend any direct exposure to sunlight in the middle of the day, when vitamin D3 stimulating UVB are strongest.

We routinely seek removal of solar keratoses, and basal and squamous cell carcinomas from our face and hands. And it is appropriate to protect those heavily exposed areas with sunscreens.

Yet, our capacity to make vitamin D is also restricted by sunscreens and our inability to open windows in our workplaces. Applying suncreens commonly blocks 95% of vitamin D-stimulating UVB light, as does glass.

Sunbathing before a closed window that allows through damaging UVA, but not beneficial UVB, is much more risky than exposing your tummy, back or legs to direct sun.

To maintain vitamin D levels, all most of us need to do is expose one of these large areas of our body to direct midday sunshine in winter (or mid-morning or mid-afternoon sun in summer) for 10 to 15 minutes or until the skin is lightly pink.

Meanwhile, continue to protect your face and hands with sunscreens for cosmetic purposes and to limit chronic over-exposure.

Darker skinned people and those living further away from the equator (Hobart instead of Cairns, for instance) will require slightly longer exposure. It's as simple as sitting in your garden or before an open window, letting direct sunlight onto skin exposed through rolling up your sleeves, trouser legs, or the bottom of your shirt.

It's time we had a conversation about sensible sunlight exposure of our otherwise hidden bodies; particularly since this potential antidote to the epidemic of autoimmune diseases of various types raging in our community is so readily available and inexpensive.

It's not your face and hands, but your tummy and back that need to be exposed more often to direct sunlight for brief periods. It's a question of using sunlight appropriately and getting your gear off in sensible moderation.

Provided by The Conversation

This story is published courtesy of The Conversation (under Creative Commons-Attribution/No derivatives).

Vitamin D reduces blood pressure and relieves depression in women with diabetes

In women who have type 2 diabetes and show signs of depression, vitamin D supplements significantly lowered blood pressure and improved their moods, according to a pilot study at Loyola University Chicago Niehoff School of Nursing.

26 jun 2013--The study was presented at the American Diabetes Association 73rd Scientific Sessions in Chicago.

"Vitamin D supplementation potentially is an easy and cost-effective therapy, with minimal side effects," said Sue M. Penckofer, PhD, RN, lead author of the study and a professor in the Niehoff School of Nursing. "Larger, randomized controlled trials are needed to determine the impact of vitamin D supplementation on depression and major cardiovascular risk factors among women with Type 2 diabetes."

Penckofer recently received a four-year, $1.49 million grant from the National Institute of Nursing Research at the National Institutes of Health to do such a study. Penckofer and her Loyola co-investigators plan to enroll 180 women who have type 2 diabetes, symptoms of depression and insufficient levels of vitamin D. Women will be randomly assigned to receive either a weekly vitamin D supplementation (50,000 International Units) or a matching weekly placebo for six months. The study is titled "Can the Sunshine Vitamin Improve Mood and Self Management in Women with Diabetes?

About 1 in 10 people in the United States has diabetes, and the incidence is projected to increase to 1 in 4 persons by 2050. Women with type 2 diabetes have worse outcomes than men. The reason may be due to depression, which affects more than 25 percent of women with diabetes. Depression impairs a patient's ability to manage her disease by eating right, exercising, taking medications, etc.

Many Americans do not get enough vitamin D, and people with diabetes are at especially high risk for vitamin D insufficiency or deficiency. Reasons include limited intake of foods high in vitamin D, obesity, lack of sun exposure and genetic variations.

The pilot study included 46 women who were an average age of 55 years, had diabetes an average of 8 years and insufficient blood levels of vitamin D (18 ng/ml). They took a weekly dose (50,000 International Units) of vitamin D. (By comparison, the recommended dietary allowance for women 51 to 70 years is 600 IU per day.)

After six months, their vitamin D blood levels reached sufficient levels (average 38 ng/ml) and their moods improved significantly. For example, in a 20-question depression symptom survey, scores decreased from 26.8 at the beginning of the study (indicating moderate depression) to 12.2 at six months (indicating no depression. (The depression scale ranges from 0 to 60, with higher numbers indicating more symptoms of depression.)

Blood pressure also improved, with the upper number decreasing from 140.4 mm Hg to 132.5 mm Hg. And their weight dropped from an average of 226.1 pounds to 223.6 pounds.

Penckofer is internationally known for her research on vitamin D, diabetes and depression. In October, she will be inducted as a Fellow in the American Academy of Nursing for her scientific contributions in improving the health and quality of life of women with chronic disease. And she recently was appointed as the first nurse researcher to the Chicago Diabetes Center for Translational Research.

Provided by Loyola University Health System

Vitamin D supplement fails to lower cholesterol in short term

Taking vitamin D supplements to compensate for vitamin D deficiency didn't improve cholesterol—at least in the short term, according to new research in Arteriosclerosis, Thrombosis and Vascular Biology, an American Heart Association journal.

07 sept 2012--Researchers studied 151 people with vitamin D deficiency who received either a mega-dose (50,000 internationals units) of vitamin D3 or placebo weekly for eight weeks. Participants' cholesterol levels were measured before and after treatment.

Correcting vitamin D deficiencies with high doses of oral vitamin D supplements did not change cholesterol levels, researchers found. This was despite effectively increasing vitamin D to recommended levels. Vitamin D levels nearly tripled in the group that received actual supplements, but were unchanged in the placebo group.

"Our study challenges the notion that vitamin D repletion improves cholesterol levels" said Manish Ponda, M.D., M.S., study lead author and assistant professor of clinical investigation in Dr. Jan Breslow's laboratory of biochemical genetics and metabolism at The Rockefeller University in New York, N.Y. "These clinical trial results confirm those from a recent data mining study."

The researchers also tested the effect of vitamin D supplementation on more sophisticated biomarker measures of cholesterol, such as particle size and number. "These measures of cholesterol, which are not used in routine clinical practice, also did not change in response to vitamin D therapy," Ponda said.

As expected, replenishing subjects with high-dose supplements of oral vitamin D decreased parathyroid hormone levels and increased calcium levels—physical functional changes that were linked to participants' increase in low-density lipoprotein (LDL, bad cholesterol).

"For example, participants receiving vitamin D who had an increase in calcium levels experienced a 7 percent increase in LDL cholesterol, while those whose calcium levels fell or did not change had a 5 percent decrease in LDL cholesterol," Ponda said.

The study questions the use of vitamin D supplements to improve cholesterol, Ponda said. While the dose of vitamin D in this study was high, it was appropriate for correcting a vitamin D deficiency over an eight week period.

However, longer-term studies on the impact of the changes in LDL cholesterol as a result of high dose vitamin D supplementation are needed to make stronger recommendations. And questions remain about whether increasing vitamin D levels with exposure to sunlight, the predominant natural source, would have a different effect than with high-dose oral supplements.

To address these issues, Ponda and Breslow will begin another clinical trial this fall, comparing the effect of oral vitamin D to ultraviolet light exposure with a longer follow-up period.

Provided by American Heart Association

Calcium, vitamin D modulate human energy metabolism

13 march 2012--There is considerable evidence that calcium and vitamin D intake are influential in modulating energy metabolism in humans, according to a study published online March 2 in Obesity Reviews.

Mario J. Soares, M.B.B.S., Ph.D., of Curtin University in Perth, Australia, and associates conducted a literature review of randomized controlled trials (RCTs) to explore the role of calcium and vitamin D in regulating body weight and adiposity.

The researchers found consistent evidence that calcium and vitamin D increase whole body fat oxidation after meals and that calcium induces modest energy loss through increased fecal fat excretion. Equivocal evidence exists for the association with increased diet-induced thermogenesis and lipolysis, suppression of lipogenic enzymes, and decreased hunger ratings or energy/macronutrient intake. A potential improvement in insulin sensitivity has been suggested following vitamin D, which would impact food intake and substrate oxidation, but very few RCTs have explored postprandial routes of action.

"It is our opinion that calcium with or without vitamin D modulates human energy metabolism. The evidence is convincing that calcium increases fat oxidation after a single meal and over several meals of the day," the authors write. "While it is clear that nutrition and public health recommendations demand consistency of observation from a variety of study designs, the inclusion of mechanistic pathways in such investigations is essential in cementing the biological plausibility of the outcomes."

More information: Abstract

Vitamin D deficiency linked to higher mortality in female nursing home residents

The majority of institutionalized elderly female patients are vitamin D deficient and there is an inverse association of vitamin D deficiency and mortality, according to a recent study accepted for publication in The Endocrine Society's Journal of Clinical Endocrinology and Metabolism (JCEM).

7 march 2012--Recommendations for dietary vitamin D intake in the elderly are higher than any other age group because vitamin D deficiency is extraordinarily prevalent in this population and is considered a causal risk factor for skeletal diseases. Treatment involves the daily ingestion of up to 800 IU of vitamin D. The current study examined whether vitamin D deficiency is an independent risk factor for mortality in institutionalized elderly patients.

"Our findings show that the vast majority of nursing home residents are severely vitamin D deficient and those with the lowest vitamin D levels are at high risk of mortality," said Dr. Stefan Pilz, MD, of the Medical University of Graz, Austria, and lead author of the study. "This situation warrants immediate action to prevent and treat vitamin D deficiency."

In this study, researchers examined a sample of 961 nursing home residents in Austria, with an average age of 83.7 years. The researchers recorded 284 deaths—or 30 percent of the study cohort—after a mean follow-up time of 27 months. Their findings showed that vitamin D levels were below recommended levels in 92.8 percent of the study participants, suggesting that while vitamin D deficiency among frail and elderly populations has been acknowledged for several decades, no effective strategies to treat the deficiencies have been developed and implemented.

"Vitamin D supplementation in these patients can exert significant benefits on clinically relevant outcomes such as fractures," said Pilz. "In light of our findings, and the existing literature on adverse effects of vitamin D deficiency, there exists now an urgent need for effective strategies to improve vitamin D status in older institutionalized patients."

More information: The article, "Low 25-hydroxyvitamin D is associated with increased mortality in female nursing home residents," appears in the April 2012 issue of JCEM.

Provided by The Endocrine Society

Vitamin D in foods may reduce risk of depression in older women

Results of a large study among older women suggest that those who ate more of the "sunshine vitamin" were less likely to experience depression symptoms than women who consumed less of the vitamin, according to findings published this week by Elizabeth Bertone-Johnson at the University of Massachusetts Amherst School of Public Health and Health Sciences, with colleagues from several other U.S. academic centers.

10 sept 2011--Overall, a diverse population of postmenopausal women who consumed 800 international units (IU) per day of the vitamin was 20 percent less likely to have depressive symptoms than those who consumed less than 100 IU daily. Among women who had no depression at baseline, those who took in 400 IU or more of vitamin D per day from food sources also had a 20 percent lower risk of depressive symptoms three years later compared to those in the group taking in the lowest amount of vitamin D.

In terms of absolute risk for depressive symptoms and vitamin D intake, the prevalence of depressive symptoms was 10.0 percent in women reporting total vitamin D intake greater than or equal to 800 IU per day compared to 12.7 percent in those reporting less than 100 IU per day, the authors report. Their results are in the current issue of the American Journal of Clinical Nutrition.

These findings need to be confirmed in clinical trials of vitamin D and depression, say Bertone-Johnson and colleagues at institutions across the nation, but the results are provocative. "Dietary vitamin D intake and supplement use are easy for women to modify and, if shown to be effective in clinical trials, could provide new avenues for the prevention and perhaps the treatment of depression," she points out.

In addition to sunlight, fat-soluble vitamin D comes largely from eating fatty fish and fortified milk, dairy products and orange juice.

The association observed between dietary vitamin D intake and depressive symptoms was found among nearly 82,000 postmenopausal women (50 to 79 years old) recruited for the Women’s Health Initiative Observational Study, part of a larger study of older women funded by the National Heart, Lung and Blood Institute at 40 clinical centers throughout the United States from 1993 to 1998.

Participants’ vitamin D intake at baseline was measured by questionnaire and supplement use was assessed by trained interviewers. Among other questions, participants were asked to report their usual intake of 122 foods or food groups in the three previous months. The study also estimated and controlled for the average amount of sunlight residents could receive in various parts of the country.

Bertone-Johnson and colleagues examined depressive symptoms at baseline and after three years using an established eight-item scale plus information on current antidepressant use.

The analyses controlled for age, physical activity and other factors and evaluated how mean total vitamin D intake, vitamin D from food sources and vitamin D intake from supplements were associated with the prevalence of depressive symptoms at baseline and with depressive symptoms after 3 years.

Women with the highest intake of total vitamin D, greater than 800 IU daily, and vitamin D from food sources greater than 400 IU daily, each had a significantly lower prevalence of depressive symptoms compared to those reporting consuming less than 100 IU per day. Also, among women without evidence of depression at baseline, higher vitamin D intake from food sources was associated with a lower risk of depressive symptoms in the third year of follow-up.

A strength of this large study included the diversity of subjects which allowed the researchers to explore whether the association between vitamin D and depression may vary by race/ethnicity, age or other factors such as education, body mass index, smoking, alcohol use, possible sunlight exposure and physical activity.

Besides Bertone-Johnson and colleagues at the University of Massachusetts Amherst, other researchers taking part in this study were from Group Health Research Institute in Seattle, the University of Nevada School of Medicine in Reno, Drexel University School of Public Health in Philadelphia, Fred Hutchinson Cancer Research Center in Seattle, the University of Buffalo, Brigham and Women’s Hospital and Harvard Medical School in Boston; the UMass Medical School in Worcester, the University of California at Los Angeles School of Public Health, the Albert Einstein College of Medicine and Yeshiva University in Bronx, New York.

The Women’s Health Initiative is funded by the National Heart, Lung and Blood Institute at the National Institutes of Health.

More information: http://www.ajcn.or … early/recent

Provided by University of Massachusetts Amherst

Vitamin D can help elderly women survive

Giving vitamin D3 (cholecalciferol) to predominantly elderly women, mainly in institutional care, seems to increase survival. These women are likely to be vitamin D deficient with a significant risk of falls and fractures. This is the key conclusion in a systematic review published in the latest edition of The Cochrane Library.

06 july 2011--Up until now there has been no clear view on whether there is a real benefit of taking vitamin D. "A Cochrane meta-analysis published only a couple of years ago found that there was some evidence for benefit, but it could not find an effect on mortality. We were, however, aware that more trials had been published and wanted to assess the effects of vitamin D when you added all the data together," said Dr Goran Bjelakovic, who works at Department of Internal Medicine - Gastroenterology and Hepatology, at the University of Nis, in Serbia and at The Cochrane Hepato-Biliary Group at The Copenhagen Trial Unit in Copenhagen, Denmark.

The eight-strong international team of researchers identified 50 randomised trials that together had 94,148 participants. They had a mean age of 74 years, and 79% were women. "Our analyses suggest that vitamin D3 reduces mortality by about 6%. This means that you need to give about 200 people vitamin D3 for around two years to save one additional life," says Bjelakovic.

There were no significant benefits of taking other forms of vitamin D such as vitamin D2, and the active forms of the vitamin, alfacalcidol or calcitriol. However, the researchers point out that they could only find much less data relating to these types of vitamin D and so these conclusions should be taken with caution. "We need to have more randomised trials that look specifically to see whether these forms of vitamin D do or don't have benefits," says Bjelakovic. His team did conclude that alfacalcidol and calcitriol significantly increased the risk of hypercalcaemia, and vitamin D3 combined with calcium significantly increased the risk of kidney stones.

There have been reports and comments that taking vitamin D can reduce the risk of getting cancer, but this work showed no evidence that vitamin D reduced cancer-related mortality.

"Previous reviews of preventive trials of vitamin D have not included as much information and have not examined the separate influence of different forms of vitamin D on mortality. By taking data from a larger number of trials we have been able to shed much more light on this important issue," says Bjelakovic.

Provided by Wiley

Vitamin D levels linked with health of blood vessels

A lack of vitamin D, even in generally healthy people, is linked with stiffer arteries and an inability of blood vessels to relax, research from the Emory/Georgia Tech Predictive Health Institute has found.

04 april 2011--The results add to evidence that lack of vitamin D can lead to impaired vascular health, contributing to high blood pressure and the risk of cardiovascular disease. Study participants who increased their vitamin D levels were able to improve vascular health and lower their blood pressure.

The data is being presented on Sunday by Ibhar Al Mheid, MD, a cardiovascular researcher at Emory University School of Medicine, at the annual American College of Cardiology meeting in New Orleans. Al Mheid is one of five finalists for the ACC's Young Investigators Award competition in physiology, pharmacology and pathology. He is working with Arshed Quyyumi, MD, professor of medicine and director of the Emory Cardiovascular Research Institute.

The 554 participants in the study were Emory or Georgia Tech employees –average age 47 and generally healthy -- who are taking part in the Center for Health Discovery and Well Being, part of the Emory/Georgia Tech Predictive Health Institute.

The average level of 25-hydroxyvitamin D (a stable form of the vitamin reflecting diet as well as production in the skin) in participants' blood was 31.8 nanograms per milliliter. In this group, 14 percent had 25-hydroxyvitamin D levels considered deficient, or less than 20 nanograms per milliliter, and 33 percent had levels considered insufficient, less than 30 nanograms per milliliter.

The researchers monitored the ability of participants' blood vessels to relax by inflating and then removing a blood pressure cuff on their arms. To allow blood to flow back into the arm, blood vessels must relax and enlarge – a change that can be measured by ultrasound. The researchers also made other measurements of smaller blood vessels and examined the resistance to blood flow imposed by the arteries.

Even after controlling for factors such as age, weight and cholesterol, people with lower vitamin D levels still had stiffer arteries and impaired vascular function, Al Mheid says.

"We found that people with vitamin D deficiency had vascular dysfunction comparable to those with diabetes or hypertension," he says.

Throughout the body, a layer of endothelial cells lines the blood vessels, controlling whether the blood vessels constrict or relax and helping to prevent clots that lead to strokes and heart attacks.

"There is already a lot known about how vitamin D could be acting here," Al Mheid says. "It could be strengthening endothelial cells and the muscles surrounding the blood vessels. It could also be reducing the level of angiotensin, a hormone that drives increased blood pressure, or regulating inflammation."

Most Americans generally get the majority of their vitamin D from exposure to sunlight or from dietary supplements; fortified foods such as milk or cereals are a minor source. A few foods, such as oily fish, naturally contain substantial amounts of vitamin D.

Participants whose vitamin D levels increased over the next six months, either from dietary supplements or ample sun exposure, tended to improve their measures of vascular health and had lower blood pressure. Forty-two study participants with vitamin D insufficiency whose levels later went back to normal had an average drop in blood pressure of 4.6 millimeters mercury.

"This was an observational study, rather than an interventional one, and it was difficult to tease out how the people who restored their vitamin D levels got there," Al Mheid says. "We are hoping to conduct a study where we have participants take a defined regimen of vitamin D."

"With his findings showing the relationship between vitamin D deficiency and vascular dysfunction, Dr. Mheid has helped advance our understanding of the importance of Vitamin D in preventing a common health problem in aging adults," says Kenneth Brigham, MD, medical director of the Emory/Georgia Tech Center for Health Discovery and Well Being. "Additionally, ongoing health studies based on the Center's collection of health information from participants will yield more discovery as the Center continues to develop."

The Emory-Georgia Tech Predictive Health Institute is a national leader in moving the practice of medicine from a reactive, disease-focused system to a proactive health-focused system. The initiative integrates research, scholarship and education in an innovative effort aimed at revolutionizing care of people to define, preserve and prolong the health of individuals and of society.

Key areas of the Initiative include defining and measuring health using optimal biomarkers of health and understand their interrelationships, determining the best interventions to optimize health throughout an individual's or a population's lifetime.

Provided by Emory University

Vitamin D and parathyroid hormone levels may not affect cardiovascular mortality

There is burgeoning public interest in possible wide-ranging health benefits from vitamin D, including cardiovascular health. In a study published in the December 2010 issue of The American Journal of Medicine, investigators found that there was no independent association between serum levels of vitamin D or parathyroid hormone and cardiovascular mortality in this prospective study, the first in a population of older community-dwelling adults with a low prevalence of vitamin D deficiency and a broad range of kidney function.

18 dec 2010--Researchers collected data from the Rancho Bernardo study, which was established in 1972. Between 1997 and 1999, 1091 participants attended a follow-up visit where blood samples were collected, along with detailed surveys of medical history, medications, cigarette smoking, alcohol consumption, and exercise; serum levels of 25-hydroxyvitamin D (25[OH]D) (mean 42 ng/mL), 1,25-dihydroxyvitamin D (1,25[OH]2D) (median 29 pg/mL), and intact parathyroid hormone (median 46 pg/mL) were measured; mean estimated glomerular filtration rate (eGFR) was 74 mL/min/1.73 m2. Using data from 1073 participants who qualified for this study, these people were followed for a median of 6.8 years (maximum 10.7 years). During this period, there were 266 deaths, including 111 cardiovascular deaths. Of those 111, 71 had normal kidney function (eGFR > 60 mL/min/1.73 m2) and 40 had reduced kidney function (eGFR <>

In populations with chronic kidney disease, low levels of 25(OH)D and 1,25[OH]2D, and high levels of intact parathyroid hormone have been suggested to explain the association between chronic kidney disease and cardiovascular mortality. Even in people with intact kidney function, there are multiple mechanisms that could link Vitamin D and cardiovascular disease.

"To our knowledge, this is the first prospective study to investigate the role of serum 25[OH]D, 1,25[OH]2D, and intact parathyroid hormone in the prediction of cardiovascular mortality in a population of older community-dwelling adults with a low prevalence of vitamin D deficiency and a broad range of kidney function," commented Lead investigator Simerjot K. Jassal, MD, Division of General Internal Medicine and Geriatrics, Department of Medicine, University of California, San Diego, and VA San Diego Healthcare System, La Jolla.

Dr. Jassal continued, "After adjusting for age alone, there was no independent association between serum levels of 25(OH)D, 1,25(OH)2D, or intact parathyroid hormone and cardiovascular mortality. Prior published literature in community-dwelling adults suggests an increased risk of cardiovascular mortality only in individuals with vitamin D levels lower than levels observed here. Our null results may mean that only larger disruptions in levels of 25(OH)D and 1,25(OH)2D contribute to cardiovascular mortality. These null findings are also compatible with results from randomized clinical trials in which vitamin D supplementation has failed to prevent cardiovascular outcomes, although the doses of vitamin D in these trials may have been too low."

More information: The article is "Vitamin D, Parathyroid Hormone, and Cardiovascular Mortality in Older Adults: The Rancho Bernardo Study" by Simerjot K. Jassal, MD, Michel Chonchol, MD, Denise von Mühlen, MD, PhD, Gerard Smits, PhD, and Elizabeth Barrett-Connor, MD. It appears in The American Journal of Medicine, Volume 123, Issue 12 (December 2010)

Provided by Elsevier

Low and high vitamin D levels in older women associated with increased likelihood of frailty

A recent study accepted for publication in The Endocrine Society's Journal of Clinical Endocrinology & Metabolism (JCEM) found that lower and higher vitamin D levels were associated with an increased likelihood of frailty in older women. Women with vitamin D levels between 20.0 and 29.9 ng/ml were at the lowest risk of frailty.

09 dec 2010--Vitamin D deficiency and frailty are common with aging. Dimensions of frailty, including weakness and slowness are potential outcomes of vitamin D deficiency and many experts have recommended measuring vitamin D levels in older adults and prescribing vitamin D supplementation if levels are less than 30 ng/ml to prevent adverse health outcomes. This new study however found a U-shaped relationship between vitamin D levels and frailty; older women with vitamin D levels higher than 30 ng/ml and those with levels lower than 20 ng/ml were more likely to be frail.

"Vitamin D supplementation has grown in popularity, yet the association between vitamin D status and risk of adverse health outcomes in older adults is uncertain," said Kristine Ensrud, MD, professor of medicine and epidemiology, Minneapolis VA Medical Center and the University of Minnesota and lead author of the study. "Our study did not find that higher vitamin D status was associated with lower subsequent risks of frailty or death. In fact, higher levels of vitamin D were associated with increased likelihood of frailty."

In this study, researchers measured vitamin D levels and assessed frailty status in a cohort of 6,307 women aged 69 and older. To determine whether lower vitamin D levels were associated with an increased risk of greater frailty status at a later date, 4,551 women classified as non-frail at baseline had frailty status reassessed an average of 4.5 years later. They found that older women with vitamin D levels less than 20 ng/ml and more than 30 ng/ml had higher odds of frailty at baseline. Lower vitamin D levels among non-frail women at baseline were associated with an increased risk of frailty or death at follow-up.

"Evidence is lacking to support use of vitamin D supplementation for prevention of frailty and other outcomes including cancer or all-cause mortality," said Ensrud. "Our results indicate that well-designed large randomized trials of sufficient duration are needed to accurately quantify health effects of vitamin D supplementation, including whether or not supplementation reduces the incidence or progression of frailty in older adults."

More information: The article, "Circulating 25-hydroxyvitamin D Levels and Frailty Status in Older Women," appears in the December 2010 issue of JCEM.

Provided by The Endocrine Society

Report: A bit more vitamin D is good, not too much

Got milk? You may need a couple cups more than today's food labels say to get enough vitamin D for strong bones. But don't go overboard: Long-awaited new dietary guidelines say there's no proof that megadoses prevent cancer or other ailments - sure to frustrate backers of the so-called sunshine vitamin.

01 dec 2010--The decision by the prestigious Institute of Medicine, the health arm of the National Academy of Sciences, could put some brakes on the nation's vitamin D craze, warning that super-high levels could be risky.

"More is not necessarily better," cautioned Dr. Joann Manson of Harvard Medical School, who co-authored the Institute of Medicine's report being released Tuesday.

Most people in the U.S. and Canada - from age 1 to age 70 - need to consume no more than 600 international units of vitamin D a day to maintain health, the report found. People in their 70s and older need as much as 800 IUs. The report set those levels as the "recommended dietary allowance" for vitamin D.

That's a bit higher than the target of 400 IUs set by today's government-mandated food labels, and higher than 1997 recommendations by the Institute of Medicine that ranged from 200 to 600 IUs, depending on age.

But it's far below the 2,000 IUs a day that some scientists recommend, pointing to studies that suggest people with low levels of vitamin D are at increased risk of certain cancers or heart disease.

"This is a stunning disappointment," said Dr. Cedric Garland of the University of California, San Diego, who wasn't part of the institute's study and says the risk of colon cancer in particular could be slashed if people consumed enough vitamin D.

"Have they gone far enough? In my opinion probably not, but it's a step in the right direction," added prominent vitamin D researcher Dr. Michael Holick of Boston University Medical Center, who said the new levels draw needed attention to the vitamin D debate and encourage more food fortification.

Vitamin D and calcium go hand in hand, and you need a lifetime of both to build and maintain strong bones. But the two-year study by the Institute of Medicine's panel of experts concluded research into vitamin's D possible roles in other diseases is conflicting. Some studies show no effect, or even signs of harm.

A National Cancer Institute study last summer was the latest to report no cancer protection from vitamin D and the possibility of an increased risk of pancreatic cancer in people with the very highest D levels. Super-high doses - above 10,000 IUs a day - are known to cause kidney damage, and Tuesday's report sets 4,000 IUs as an upper daily limit - but not the amount people should strive for.

And Manson pointed to history's cautionary tales: A list of other supplements - vitamins C and E and beta carotene - plus menopause hormone pills that once were believed to prevent cancer or heart disease didn't pan out, and sometimes caused harm, when put to rigorous testing.

Stay tuned: To help settle the issue, Manson is heading a government-funded study that's recruiting 20,000 healthy older Americans to test whether taking 2,000 IUs of vitamin D really will lower their risk for heart disease, a stroke or certain cancers.

In the meantime, it's hard to consume 600 IUs of vitamin D from food alone. A cup of D-fortified milk or orange juice has about 100 IUs. The best sources may be fatty fish - some servings of salmon can provide about a day's supply. Other good sources are D-fortified cereals.

But here's the report's big surprise: While some people truly are seriously deficient in vitamin D, the average American in fact already has enough circulating in his or her blood - because we also make vitamin D from sun exposure, and because many people already take multivitamins or other D-containing dietary supplements.

Wait a minute: Headlines in recent years have insisted the opposite, that a majority of people don't get enough vitamin D, especially during the winter. What explains the contradiction?

Most testing laboratories are using a too-high cutoff for those blood levels, said report co-author Dr. Clifford Rosen of the Maine Medical Center. The report says at least 20 nanograms is adequate for bone health, while many labs instead list people as low if their blood levels are below 30 ng. Serious vitamin D deficiencies are diagnosed when levels dip well below 20, something that hasn't changed.

Rosen called the state of vitamin D testing "the wild, wild West," and said he hoped that "with this report, we can at least temper people's enthusiasm for just taking tons of supplements."

As for calcium, the report recommended already accepted levels to go along with your daily D - about 1,000 milligrams of calcium a day for most adults, 700 to 1,000 mg for young children, and 1,300 mg for teenagers and menopausal women. Too much can cause kidney stones; the report said that risk increases once people pass 2,000 mg a day.

It's true that most studies link poor health to vitamin D levels that are below 20 ng, said preventive cardiologist Dr. Erin Michos, a Johns Hopkins University School of Medicine professor who wasn't part of the study.

But, "I'm not sure I'm going to dramatically change my practice," said Michos, who pushes her patients to boost their levels until they're between 30 and 50 ng.

Low vitamin D increases risk of dementia in elderly

LONDON , 13 july 2010– Older people with low levels of vitamin D appear more likely to have problems with memory, learning and thinking, suggesting low vitamin D could give an early warning for dementia risk, scientists said on Monday.

Researchers from Britain, Italy and the United States studied 850 Italians aged 65 or older and found that those who were severely vitamin D deficient were 60 percent more likely to experience substantial general cognitive decline, and 31 percent more likely to experience problems with mental flexibility.

"This is the first study to identify a clear link between low vitamin D levels and cognitive decline," said David Llewellyn of the Peninsula Medical School at Britain's Exeter University, who led the study.

"We have now been able to demonstrate a connection between having low levels of vitamin D and going on to develop cognitive problems."

Since an estimated that one billion people worldwide have insufficient levels of vitamin D, Llewellyn said the findings were "a cause for real concern."

Giving vitamin D supplements to older people to boost their levels could be "a highly promising therapeutic target for the prevention of dementia," he said, particularly since supplements are cheap, safe and have already been shown to help prevent to reduce the risk of falls and fractures.

Most vitamin D is made by the body as a natural by-product of the skin's exposure to sunlight. It can also be found in a few foods such as oily fish and is vital for health, as it helps cells absorb calcium and is key for bone strength.

Some recent studies have also suggested vitamin D may protect against cancer, artery disease and tuberculosis.

In this study, Llewellyn's team found that older people who were severely deficient in vitamin D -- defined as having blood levels of 25-hydroxyvitamin D of less than 25 nanomoles per liter -- were 60 percent more likely to have substantial cognitive decline over a 6-year period studied.

They were also 31 percent more likely to show decline in a test measuring executive function than those with good vitamin D levels. The findings were published in the Archives of Internal Medicine journal.

Dementia is a brain-wasting condition that affects around 35 million people worldwide.

Its most common form is Alzheimer's disease, in which patients gradually to lose their memory, their ability to navigate and understand the world around them and to look after themselves. Despite decades of research, doctors still have few effective weapons against it.

Llewellyn's team said they thought Vitamin D may help prevent the degeneration of brain tissue by having a role in formation of nervous tissue, maintaining levels of calcium in the body, or clearing of beta-amyloid, the substance that forms the brain plaques that are associated with Alzheimer's disease.

Experts estimated that in the United States and Europe, between 40 percent to 100 percent of older adults are deficient in vitamin D and the problem is aggravated in the elderly as they spend more time indoors and their skin becomes less efficient at producing vitamin D with age.

Vitamin D Levels Linked to Cardiovascular Mortality

Lower levels among African-Americans may explain racial disparities observed in CV mortality

14 jan 2010-- Low vitamin D levels are associated with increased cardiovascular mortality, and may explain why African-Americans have higher rates of cardiovascular mortality than Caucasians, according to a study in the January/February issue of the Annals of Family Medicine.

Kevin Fiscella, M.D., of the University of Rochester School of Medicine and Dentistry in New York, and colleagues analyzed data from the third National Health and Nutrition Examination Survey 1988 to 1994 and cause-specific mortality through 2001 from the National Death Index.

Compared to subjects with the three highest quartiles of vitamin D levels, the researchers found that those in the lowest quartile had a higher adjusted risk of cardiovascular death (incident rate ratio, 1.40). They also found that the higher age- and sex-adjusted cardiovascular mortality among African-Americans (incident rate ratio, 1.38) was reduced after adjustment for vitamin D levels (incident rate ratio, 1.14) and eliminated after additional adjustment for income (incident rate ratio, 1.01).

"Randomized controlled trials of vitamin D supplementation in those with low 25(OH)D levels are needed to determine whether optimization of these levels improves outcomes from cardiovascular mortality, particularly among blacks, who bear a disproportionate burden of cardiovascular disease," the authors conclude.

Abstract
Full Text (subscription or payment may be required)

Putting limits on vitamin E

The potent antioxidant may do more harm than good, Tel Aviv University research suggests

05 jan 2010--Vitamin-fortified foods and dietary health supplements can ease health worries. But what kinds of vitamins are right for you? And how much of them should you take, and how often?

A research group from Tel Aviv University has done the most comprehensive and accurate study of clinical data on Vitamin E use and heart disease to date, and it warns that indiscriminate use of high-dose Vitamin E supplementation does more harm than good. Their results were recently reported in ATVB, a leading journal of cardiology, and discussed in the journal BioFactors.

"There were so many conflicting reports about Vitamin E and its effect on various diseases, particularly heart disease, that we wanted to set the record straight," says Prof. Dov Lichtenberg of TAU's Sackler School of Medicine.

"Our new study shows that some people may be harmed by the treatment, whereas others may benefit from it. Now we're trying to identify groups of people that are most likely to benefit from the effects of Vitamin E," adds study co-researcher Dr. Ilya Pinchuk. The TAU research team also included decision analyst Dr. Moshe Leshno of the Sackler Faculty of Medicine and the Leon Recanati Faculty of Management and Dr. Yedidya (Didi) Dotan, whose PhD thesis is the basis for this analysis.

A longer life without it?

Applying a very different approach than any previous study, the team of researchers put their heads together to draw definitive conclusions about Vitamin E. In their publication in ATVB the Tel Aviv University researchers evaluated the results of the prominent studies measuring the health benefits of Vitamin E but reached varying conclusions. There have been many previous publications on the subject. Analysis of the results of all these past publications together revealed that subjects who did not take a Vitamin E supplement enjoyed more quality-adjusted-life-years (QALY), a standard parameter used in medicine to assess the effect of medical interventions.

"To explain the meaning of this parameter," says Dr. Pinchuk, "consider a participant who was healthy during the first 10 out of 20 years of the study, but then suffered a stroke and became dependent on others throughout the following 10 years. The QALY during the first 10 years of healthy life is 10, but after the stroke the quality of life is only half of what this person had before. Therefore, the second decade is considered the equivalent of merely 5 years of healthy life and in sum a person's QALY is 15.

The researchers examined data from more than 300,000 subjects in the US, Europe and Israel. "Our major finding," says Dr. Pinchuk, "was that the average quality-adjusted life years (QALY) of Vitamin E- supplemented individuals was 0.30 less than that of untreated people. This, of course, does not mean that everybody consuming Vitamin E shortens their life by almost 4 months. But on average, the quality-adjusted longevity is lower for vitamin-treated people. This says something significant."

Overturning earlier studies

In the BioFactors article, the TAU researchers defined "the real challenge as being able to identify who is likely to benefit taking Vitamin E." They also explored the first hypothesis of the oxidative theory of atherosclerosis published more than 20 years ago, which was the basis for the widespread use of antioxidants today. At first, this hypothesis raised great enthusiasm that anti-oxidants like Vitamins E and C and flavonoids could be used to prevent disease or its progression. In this respect, the new findings are very disappointing.

"We've now concluded that going to the grocery or to a health food store to buy Vitamin E supplements, for the most part, won't do you good. In some cases it can do harm," says Dr. Pinchuk. "A doctor wouldn't prescribe anti-hypertension drugs to the whole population, only to those with low blood pressure. It seems this is true for antioxidants, too. When you give them to everybody, you may be doing more harm than good. Some people may benefit from it, but more may be harmed."

The researchers are now building sets of criteria that detail under what conditions Vitamin E supplements should be taken. They are also investigating the chemical mechanisms of antioxidants in general to better understand how they work.

###

American Friends of Tel Aviv University (www.aftau.org) supports Israel's leading and most comprehensive center of higher learning. In independent rankings, TAU's innovations and discoveries are cited more often by the global scientific community than all but 20 other universities worldwide.

Internationally recognized for the scope and groundbreaking nature of its research programs, Tel Aviv University consistently produces work with profound implications for the future.

New study links vitamin D deficiency to cardiovascular disease and death

Study finds inadequate levels of vitamin D may significantly increase risk of stroke, heart disease and death

MURRAY, UT, 18 nov 2009 – While mothers have known that feeding their kids milk builds strong bones, a new study by researchers at the Heart Institute at Intermountain Medical Center in Salt Lake City suggests that Vitamin D contributes to a strong and healthy heart as well – and that inadequate levels of the vitamin may significantly increase a person's risk of stroke, heart disease, and death, even among people who've never had heart disease.

For more than a year, the Intermountain Medical Center research team followed 27,686 patients who were 50 years of age or older with no prior history of cardiovascular disease. The participants had their blood Vitamin D levels tested during routine clinical care. The patients were divided into three groups based on their Vitamin D levels – normal (over 30 nanograms per milliliter), low (15-30 ng/ml), or very low (less than 15 ng/ml). The patients were then followed to see if they developed some form of heart disease.

Researchers found that patients with very low levels of Vitamin D were 77 percent more likely to die, 45 percent more likely to develop coronary artery disease, and 78 percent were more likely to have a stroke than patients with normal levels. Patients with very low levels of Vitamin D were also twice as likely to develop heart failure than those with normal Vitamin D levels.

Findings from the study will be presented at the American Heart Association's Scientific Conference on Monday, Nov. 16 in Orlando, Florida.

"This was a unique study because the association between Vitamin D deficiency and cardiovascular disease has not been well-established," says Brent Muhlestein, MD, director of cardiovascular research of the Heart Institute at Intermountain Medical Center and one of the authors of the new study. "Its conclusions about how we can prevent disease and provide treatment may ultimately help us save more lives."

A wealth of research has already shown that Vitamin D is involved in the body's regulation of calcium, which strengthens bones — and as a result, its deficiency is associated with musculoskeletal disorders. Recently, studies have also linked Vitamin D to the regulation of many other bodily functions including blood pressure, glucose control, and inflammation, all of which are important risk factors related to heart disease. From these results, scientists have postulated that Vitamin D deficiency may also be linked to heart disease itself.

"Utah's population gave us a unique pool of patients whose health histories are different than patients in previous studies," Dr. Muhlestein says. "For example, because of Utah's low use of tobacco and alcohol, we were able to narrow the focus of the study to the effects of Vitamin D on the cardiovascular system."

The results were quite surprising and very important, says Heidi May, PhD, MS, an epidemiologist with the Intermountain Medical Center research team and one of the study authors.

"We concluded that among patients 50 years of age or older, even a moderate deficiency of Vitamin D levels was associated with developing coronary artery disease, heart failure, stroke, and death," she says. "This is important because Vitamin D deficiency is easily treated. If increasing levels of Vitamin D can decrease some risk associated with these cardiovascular diseases, it could have a significant public health impact. When you consider that cardiovascular disease is the leading cause of death in America, you understand how this research can help improve the length and quality of people's lives."

Because the study was only observational, definitive links between Vitamin D deficiency and heart disease could not be assigned — but the findings create an impetus for further study, says Dr. Muhlestein.

"We believe the findings are important enough to now justify randomized treatment trials of supplementation in patients with Vitamin D deficiency to determine for sure whether it can reduce the risk of heart disease," he says.

Vitamin D May Improve Melanoma Survival

02 oct 2009-- Higher levels of vitamin D are linked to less severe, less deadly melanoma lesions in people with skin cancer, new research suggests.

The findings provide more support for the idea that vitamin D is crucial to skin health. Many Americans, however, don't get enough of it, perhaps because they limit sun exposure and drink less milk than in the past.

"Although avoiding sunburn is very important in order to prevent melanoma, it is also important to avoid becoming deficient in vitamin D," said Dr. Julia A. Newton-Bishop, a dermatology professor at the University of Leeds in England and a study co-author. "This is especially important for melanoma patients in whom low vitamin D levels appear to be harmful."

Newton-Bishop and her research colleagues looked at the medical records of 872 people with melanoma and tried to link their vitamin D levels to the severity of their lesions and their likelihood of surviving without a relapse.

Those with higher levels of vitamin D in their bodies had less severe lesions -- the lesions were thinner -- and a lower rate of relapse, the researchers found.

The results are reported in the Sept. 14 issue of the Journal of Clinical Oncology.

"The research suggests that low levels of vitamin D allow the melanoma tumors to grow better and, therefore, to be more of a threat to the patient," Newton-Bishop said.

It's not clear how food, sun exposure and supplements contributed to the higher levels of vitamin D in some people, although they did take more multivitamins and cod liver oil, she said.

Melanoma is the cause of most skin cancer deaths, even though it accounts for less than 5 percent of skin cancer cases. The best way to prevent melanoma is by avoiding excessive sun exposure.

To boosts levels of vitamin D, people with melanoma should take daily supplements, the authors concluded, and consume foods that contain vitamin D, such as fatty fish and some fortified cereals.

The study is provocative and "somewhat contrary to traditional thinking," said Dr. Adit Ginde, an assistant professor of surgery at the University of Colorado Denver School of Medicine. More work needs to be done to prove that vitamin D levels directly affect skin cancer development and to determine if increasing the levels will help people with melanoma, he said.

Vitamin D appears to be more than a cancer fighter. Low levels of vitamin D have been linked to a variety of health problems, including heart disease, infections and poor overall health. And adults with low levels may suffer from lower bone mineral density.

But researchers have noticed that vitamin D deficiency has been on the rise in recent decades. An earlier study led by Ginde found that more than 75 percent of Americans don't have high enough vitamin D levels, with African-Americans and Latinos at especially high risk.

Vitamin D is naturally present in few foods, and some researchers recommend supplements containing as many as 2,000 International Units (IU) of vitamin D for many people, and even more for those who are obese.

The current recommendations, however, are 200 to 600 units a day, depending on age.

More information

The U.S. National Library of Medicine has more on vitamin D.

AHA/HBP: Low Vitamin D Connected to Hypertension

Women with deficient levels have a tripled risk of systolic hypertension 14 years later

28 sept 2009-- Younger women with low vitamin D levels may have a tripled risk of subsequently developing systolic hypertension, according to research presented this week at the American Heart Association's 63rd High Blood Pressure Research Conference, held from Sept. 23 to 26 in Chicago.

Flojaune C. Griffin, of the University of Michigan in Ann Arbor, and colleagues studied 559 Caucasian women who were ages 24 to 44 years when first assessed in 1993, at which time the prevalence of 25-OH-D deficiency was 81 percent. When the subjects were assessed again in 2007, the prevalence of diagnosed hypertension (systolic and diastolic) was 19 percent.

After adjusting for age, fat mass, anti-hypertensive medication use, and smoking, the researchers found that women with a vitamin D deficiency in 1993 were significantly more likely to have systolic hypertension in 2007 (risk ratio, 3.0) but not diastolic hypertension.

"These results suggest that early vitamin D deficiency may increase the long-term risk of hypertension in women at mid-life," the authors conclude.

Insufficient levels of vitamin D puts elderly at increased risk of dying from heart disease

22 sept 2009--A new study by researchers at the University of Colorado Denver and Massachusetts General Hospital (MGH) shows vitamin D plays a vital role in reducing the risk of death associated with older age. The research, just published in the Journal of the American Geriatrics Society, evaluated the association between vitamin D levels in the blood and the death rates of those 65 and older. The study found that older adults with insufficient levels of vitamin D die from heart disease at greater rates that those with adequate levels of the vitamin.

"It's likely that more than one-third of older adults now have vitamin D levels associated with higher risks of death and few have levels associated with optimum survival," said Adit Ginde, MD, MPH, an assistant professor at the University of Colorado Denver School of Medicine's Division of Emergency Medicine and lead author on the study. "Given the aging population and the simplicity of increasing a person's level of vitamin D, a small improvement in death rates could have a substantial impact on public health."

Older adults are at high risk for vitamin D deficiency because their skin has less exposure to the sun due to more limited outdoor activities as well as reduced ability to make vitamin D.

The study analyzed data from the Third National Health and Nutrition Examination Survey conducted by the National Center for Health Statistics. The research team analyzed vitamin D in blood samples of more than 3,400 participants that were selected to be representative of the 24 million older adults in the United States. Compared to those with optimal vitamin D status, those with low vitamin D levels were 3 times more likely to die from heart disease and 2.5 times more likely to die from any cause.

Dr. Ginde says the findings suggest that current daily recommendations of vitamin D may not be enough for older adults to maintain optimal health. The research team has applied for research funding from the National Institutes of Health to perform a large, population-based clinical trial of vitamin D supplementation in older adults to see if it can improve survival and reduce the incidence of heart disease.

"Confirmation of these results in large randomized trials is critically important for advancing public health," says Carlos Camargo, MD, DrPH, of the MGH Department of Emergency Medicine, the senior author of the study and an associate professor of medicine at Harvard Medical School.

The study looking at elderly death rates is the second of two studies by the same team of researchers on vitamin D and general health. The first study, published in Archives of Internal Medicine earlier this year, identified vitamin D as playing a significant role in boosting the immune system and warding off colds and flu.

"Vitamin D has health effects that go beyond strong bones," says Ginde. "It's likely that it makes a vital contribution to good health."

###

Faculty at the University of Colorado Denver's School of Medicine work to advance science and improve care. These faculty members include physicians, educators and scientists at University of Colorado Hospital, The Children's Hospital, Denver Health, National Jewish Health, and the Denver Veterans Affairs Medical Center. Degrees offered by the UC Denver School of Medicine include doctor of medicine, doctor of physical therapy, and masters of physician assistant studies. The School is located on the University of Colorado's Anschutz Medical Campus, one of four campuses in the University of Colorado system. For additional news and information, please visit the UC Denver newsroom online (http://ucdenver.edu/about/newsroom/Pages/Newsroom.aspx).

Study Shows How Low Vitamin D May Influence Heart Risk

In patients with diabetes, vitamin D associated with decreased formation of foam cells

30 aug 2009-- In people with diabetes, vitamin D may inhibit foam cell creation by reducing acetylated or oxidized low-density lipoprotein (LDL) cholesterol uptake in macrophages, according to research published in the Aug. 25 issue of Circulation.

Jisu Oh, of Washington University in St. Louis, and colleagues analyzed data from macrophages from obese diabetics with hypertension and vitamin D deficiency and four other control groups varying in these factors. Macrophages were cultured in media that contained 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃) or that was vitamin D deficient, and then exposed to LDL cholesterol.

The researchers found that, in diabetic patients, 1,25(OH)₂D₃ -- the active form of vitamin D -- suppressed foam cell formation. Deleting the vitamin D receptor in macrophages from patients with diabetes sped up modified LDL-induced foam cell formation.

"In this study, we demonstrate that activation of vitamin D receptor signaling prevents foam cell formation by reducing modified LDL cholesterol uptake in macrophages from diabetic patients. Through suppression of endoplasmic reticulum stress and c-Jun N-terminal kinase activation, 1,25(OH)₂D₃ downregulates two critical scavenger receptors involved in macrophage cholesterol deposition. Impairment of vitamin D receptor signaling confirmed acceleration of foam cell formation in diabetics. Taken together, these results suggest that modulation of vitamin D signaling is a potential therapeutic target to prevent vascular disease progression," the authors write.

Abstract
Full Text (subscription or payment may be required)