1,25(OH)2D3 plays an immunomodulatory role in the prevention of T1DM, through the vitamin D receptor (VDR) expressed in antigen presenting cells, activated T cells [9], and pancreatic islet β-cells [10]; this has been demonstrated in many trials done on nonobese diabetic mice (NOD)—a murine model of human IDDM, spontaneously developing diabetes mellitus (DM)—using 1,25(OH)2D3 or its analogue (1,25(OH)2D3, MC1288 (20-epi-1,25(OH)2D3), or KH1060 (1,25(OH)2-20-epi-22-oxa-24,26,27,-trishomovitamin D) [9]. This evidence concerns the gene VDR and diabetes mellitus.