Vitamin D in atherosclerosis, vascular disease, and endothelial function.

Vitamin D deficiency has been linked to an increased risk of hypertension, diabetes, congestive heart failure, peripheral arterial disease, myocardial infarction, stroke, and related mortality, even after adjustment for traditional cardiovascular risk factors. Accumulating evidence from experimental, clinical, and epidemiological studies suggests that vitamin D may also be associated with several indices of vascular function, including the development and progression of atherosclerotic cardiovascular disease. These findings may provide at least a partial explanation for several recent epidemiologic studies implicating low vitamin D status in the pathogenesis of cardiovascular disease. However, many questions still remain. Only a handful of studies are currently available, and the results of these studies have generally been mixed. Additionally, it is unknown whether findings differ across varied subpopulations, including minority subgroups in the United States, younger adults, and those residing in areas with varying amounts of regular sunlight. Furthermore, the exact mechanism by which vitamin D may influence the atherosclerotic disease process has not yet been completely elucidated. In addition, if vitamin D is important in the etiology of atherosclerosis, it is unclear at what stage(s) in the atherosclerotic disease process vitamin D may exert its effects. Large-scale, well-conducted, placebo controlled clinical trials testing the efficacy of vitamin D supplementation in delaying, slowing, or reverting the atherosclerotic disease process have not yet been conducted. Until the results of these studies are available, we believe it is premature to recommend vitamin D as a therapeutic option in atherosclerosis.