Vitamin D is an important pro-hormone for optimal intestinal calcium absorption for mineralization of bone. Since the vitamin D receptor is present in multiple tissues, there has been interest in evaluating other potential functions of vitamin D, particularly in cardiovascular diseases. Cross-sectional studies have reported that vitamin D deficiency is associated with increased risk of cardiovascular disease, including hypertension, heart failure and ischemic heart disease. Initial prospective studies have also demonstrated that vitamin D deficiency increases the risk of developing incident hypertension or sudden cardiac death in individuals with pre-existing cardiovascular disease. Very few prospective clinical studies have been conducted to examine the effect of vitamin D supplementation on cardiovascular outcomes. The mechanism for how vitamin D may improve cardiovascular disease outcomes remains obscure; however, potential hypotheses include the down regulation of the renin-angiotensin-aldosterone system, direct effects on the heart and vasculature or improvement of glycemic control. This review will examine the epidemiologic and clinical evidence for vitamin D deficiency as a cardiovascular risk factor and to explore potential mechanisms for the cardio-protective effect of vitamin D.
Keywords: Vitamin D, cholecalciferol, ergocalciferol cardiovascular disease, hypertension