Vitamin D: Cardiac benefits uncertain
Its value in cardiovascular disease prevention has not been confirmed.
Various studies have suggested that higher blood levels of vitamin D may help prevent heart disease, stroke, hypertension, and diabetes. The concept makes sense, because the body converts vitamin D to calcitriol, which inhibits the growth of atherosclerotic plaques and the inflammation inside them. Calcitriol also helps to maintain normal blood pressure, and may play a key role in the production and regulation of insulin, a key component in diabetes.
But the Institute of Medicine (IOM), a leading group of experts, has stopped short of recommending vitamin D supplements for cardiovascular disease prevention. It calls the data "inconclusive."