Role of vitamin D in cardiovascular diseases

Vitamin D represents a group of secosteroids involved in the calcium and phosphate metabolism. The active form of vitamin D, 1,25-dihydroxylcalciferol, exerts its biological mechanisms via the VDR (vitamin D receptor) which acts as a regulator of several target genes. Hypovitaminosis D is associated with many diseases, which are not only limited to the metabolism of the skeleton, but growing evidence links the deficit of vitamin D to cardiovascular, metabolic, immune, and neoplastic diseases. In regard to the cardiovascular system, current evidence shows the presence of VDR in endothelial cells. Moreover, both in vitro and animal experimental models demonstrated that the deficit of vitamin D can promote endothelial dysfunction and atherosclerosis development. Vitamin D can interfere with vascular functions also by affecting the production of vasodilator mediators. VDR is also expressed in left ventricle cardiomyocytes, and hypovitaminosis D can relate to cardiac hypertrophy and heart failure. Randomized clinical trials (RCT) designed to prove the therapeutic role of vitamin D supplementation have been inconclusive to date. The aim of this review is to highlight the main interactions between vitamin D metabolism and cardiovascular diseases; thus, focusing on pathogenic mechanisms and related clinical manifestations.