Additional evidence for the link between vitamin D and autoimmunity is found on the genome level as single nucleotide polymorphisms (SNPs) in three key vitamin D metabolism genes (i.e., DHCR7 and CYP2R1: determinants of circulating 25-(OH)D3, and CYP27B1: vitamin D signaling in T-lymphocytes) and VDR genes (i.e., TaqI and BsmI) have been linked to an increased risk of respectively T1D and MS [116,133,134]. Here, VDR is linked to type 1 diabetes mellitus.