Vitamin D Deficiency-A Potential Role in Cardiovascular Disease Prevention

Inadequate levels of vitamin D are associated with an increase in the risk of cardiovascular disease and death, a new observational study has found. Dr Tami L Bair (Intermountain Medical Center, Murray, UT) reported the findings here at the American Heart Association 2009 Scientific Sessions.

Bair and colleagues followed more than 27 000 people 50 years or older with no history of cardiovascular disease for just over a year and found that those with very low levels of vitamin D (<15 ng/mL) were 77% more likely to die, 45% more likely to develop coronary artery disease, and 78% more likely to have a stroke than those with normal levels (>30 ng/mL). Those deficient in vitamin D were also twice as likely to develop heart failure as those with normal levels.

"We concluded that even a moderate deficiency of vitamin D was associated with developing coronary artery disease, heart failure, stroke, and death," said coauthor Dr Heidi May (Intermountain Medical Center). However, "it is not known whether this is a cause and effect relationship," she told heartwire. Because this study was observational, more research is needed "to better establish the association between vitamin D deficiency and cardiovascular disease," she noted.

Evidence so far suggestive of benefit of vitamin D

Vitamin D was the subject of much discussion in a general session on vitamins at the AHA scientific sessions. While there is strong evidence supporting the benefits of vitamin D in cardiovascular disease, there have been only a few randomized clinical trials, and previous observational studies "show no robust effects," said Dr Harald Dobnig (Medical University of Graz, Austria). The latter suffer from limitations, such as doses of vitamin D supplementation that are too low, low compliance rates, and short study duration, he noted.

There are some large randomized trials underway looking at outcomes with vitamin D; it is hoped that they will provide definitive answers in five to seven years, Dr Eric Rimm (Harvard School of Public Health, Boston, MA) explained.

"I think there's promise for vitamin D. We know that most people have insufficient vitamin D levels in their blood," Rimm says. "So although it will take five years until some of the trials that are adequately powered to look at cardiovascular disease with vitamin D will report, the epidemiology right now is suggestive that people should have 1000 or 2000 IU of vitamin D a day," he said.
________________________
Kardea Nutrition, guided by the recommendations fo the National Cholesterol Education Program, enables each of us optimize the power of therapeutic nutrition to advance cardiovascular health, naturally and deliciously.

Major Study Looks to Nutritional Supplements & Heart Health

Boston researchers are launching a large, national trial of vitamin D and fish oil to see whether the dietary supplements reduce the risk of developing cancer or cardiovascular disease. They are also testing the idea that lower levels of vitamin D might explain higher rates of these diseases among African-Americans.

Boston researchers are launching a large, national trial of vitamin D and fish oil to see whether the dietary supplements reduce the risk of developing cancer or cardiovascular disease. They are also testing the idea that lower levels of vitamin D might explain higher rates of these diseases among African-Americans.

Dr. JoAnn Manson and Dr. Julie Buring, both of Harvard Medical School and Brigham and Women’s Hospital, hope to enroll 20,000 healthy older people in the $20 million study funded by the National Institutes of Health.

One quarter of the participants will be black. The researchers believe higher rates of cancer, heart disease, and stroke among blacks, compared with whites, might be related to dark skin’s lower ability to make vitamin D from absorbing sunlight, and they want to establish whether taking vitamin D supplements could reduce or eliminate these disparities.

“African-Americans have a higher risk of vitamin D deficiency and a greater frequency of certain types of cancer and diabetes and hypertension, so I think that it will be of great importance to look at whether something as simple as taking a vitamin D supplement can narrow these health gaps,’’ said Manson, who believes the study is one of the first large-scale randomized trials to target a specific group at higher risk for a deficiency of nutrients. “It would be wonderful if something as simple as a vitamin D pill could narrow that health gap.’’

Women over 65 and men over 60 with no history of cancer or cardiovascular disease will be randomly assigned into four groups.

Some will take daily pills with about 2,000 international units of vitamin D and about 1 gram of fish oil. Others will take pills containing no active ingredients. In the two other groups, participants will get one of the supplements and one placebo. “I think it’s important to be cautiously optimistic and not jump on the bandwagon to take megadoses of supplements before a clinical trial helps to clarify their role.’’

Treatment will last five years. Participants will not need to travel to Boston because study forms and pills will be mailed, according to www.vitalstudy.org, the website for the study.

_________________
Selected nutrients already have been found to promote cardiovascular health, notably plant sterol, soluble fibers from oatmeal, barley, psyllium and beans, and mono and polyunsatured fats in place of saturated fats. For more information on nutritional approaches to cardiovascular health, go to Kardea Nutrition. For heart health cooking recipes incorporating these key nutrients, go to Kardea Gourmet