VDR and COVID-19: However, considering that the vitamin D receptor coding gene transcription can regulate about 3% of the human genome, and that vitamin D receptors are present in several tissues (e.g., parathyroid cells, renal tubules, pancreatic β cells, immune system cells, neural cells, cardiac musculature, the muscular layer of vessels and the endothelium), many studies have suggested that vitamin D deficiency may contribute to the pathogenesis of conditions such as autoimmune diseases, cancer, COVID-19, glucose and lipid alterations, AH, MS, endothelial dysfunction, and CVD [2,7,8,9,28,29,30,31,32,33]