Vitamin D Supplements May Reduce Risk of Heart Disease Mortality

Vitamin D Supplements May Reduce Risk of Heart Disease Mortality

SAN FRANCISCO--Women who use vitamin D supplements may have a reduced risk of mortality from coronary heart disease than women who do not, according to Paul Varosy, M.D., and colleagues from the University of California, who presented their findings at the American Heart Association's Asia Pacific Scientific Forum on April 23 in Honolulu. Varosy and his colleagues analyzed data from the Study of Osteoporitic Fractures (SOF).

The investigators studied 9,704 ambulatory women (age 65 and older) who were enrolled in SOF, with 4,273 women reporting taking a supplement that contained vitamin D. It is unknown what amounts of vitamin D the women were taking, or in what form. Researchers analyzed the information to discover if there was a link between vitamin D intake and the risk of death from cardiovascular events. This link was studied because earlier research had suggested low blood levels of vitamin D might play a role in the calcification that can contribute to heart disease. In addition, co-author Warren S. Browner, M.D., noted that women with osteoporosis are more likely to die of cardiovascular diseases than women without osteoporosis.

During a mean follow-up of 11.3 years, 448 women who had enrolled in SOF died from coronary heart disease, with risk of mortality 37 percent lower in women who reported taking vitamins. After adjusting for major cardiac risk factors, calcium supplement use and self-reported health status, the risk of coronary heart disease mortality was 31 percent less in the women who reported supplement use. Researchers concluded that older women who use vitamin supplements that contain vitamin D are at decreased risk for coronary heart disease mortality, although more research would be needed to make any definitive claims in this realm.

One of the reasons to be skeptical of these results is the fact that exact vitamin supplement use is unknown, as is dietary information, according to Varosy. Additionally, he noted that multivitamin supplement use could impact these results, as could vitamin D intake from the sun. All four research centers from which SOF patients were enrolled were within 4 degrees latitude of each other, making it impossible to determine whether sunshine affected the study, according to Varosy.

"We're planning on studying dietary intake and the effect of latitude, and we're planning to find other places where we can sort out the issue of whether it's vitamin D or other components," he explained. "But the ones that are of the biggest concern to us are vitamin B6, vitamin B12 and folic acid, which are in multivitamin tablets. Those together have been shown pretty well to lower levels of homocysteine, which is an important risk factor for heart disease.

"There are well-established reasons for taking calcium and vitamin D for the prevention of osteoporosis in women who are predisposed," Varosy continued. "Anyone who is thinking about doing it, however, should talk to their doctor. That said, the downsides of taking calcium or vitamin D are very minimal. ... However, even with that, again, most people would say it's too early to have people start to take vitamin D for [cardiovascular health]. We need a lot more research before we can really recommend that on a wholesale basis."