| A report published in the January 8, 2007 issue of Circulation: A Journal of the American Heart Association revealed the discovery of Framingham Heart Study researchers that having deficient levels of vitamin D is associated with double the risk of experiencing a cardiovascular event, including heart attack, heart failure or stroke, within a five year period compared to individuals with normal levels. For the current study, Harvard Medical School assistant professor of medicine Thomas J. Wang, MD and colleagues evaluated data from 1,739 offspring of Framingham Heart Study participants. The subjects, whose average age was 59 and who had no evidence of cardiovascular disease upon enrollment, were tested for serum vitamin D levels and followed for an average of 5.4 years, during which they received periodic physical examinations and lab assessments of cardiovascular risk factors. Evaluation of vitamin D concentrations found that only 10 percent of the participants had optimal levels of over 30 nanograms per milliliter. Twenty-eight percent were found to have levels that were less than half the optimal level, and 9 percent had concentrations lower than 10 ng/mL. Analysis of the data determined that having deficient blood levels of vitamin D at below 15 nanograms per milliliter doubled the risk of having a cardiovascular event over follow up, compared to those with normal levels. After adjustment for conventional cardiovascular risk factors, the risk remained 62 percent higher than that experienced by non-deficient individuals. In a separate analysis of 688 of the participants, hypertension was found to double event risk among vitamin D deficient individuals after adjustment for traditional cardiovascular risk factors. “Vitamin D deficiency is associated with increased cardiovascular risk, above and beyond established cardiovascular risk factors,” Dr Wang stated. “The higher risk associated with vitamin D deficiency was particularly evident among individuals with high blood pressure.” “Low levels of vitamin D are highly prevalent in the United States, especially in areas without much sunshine,” he observed. “Twenty to 30 percent of the population in many areas has moderate to severe vitamin D deficiency.” “A growing body of evidence suggests that low levels of vitamin D may adversely affect the cardiovascular system,” he continued. “Vitamin D receptors have a broad tissue distribution that includes vascular smooth muscle and endothelium, the inner lining of the body’s vessels. Our data raise the possibility that treating vitamin D deficiency, via supplementation or lifestyle measures, could reduce cardiovascular risk.” | 
