CYP2R1 and type 1 diabetes mellitus: The allele distribution of CYP2R1 (rs1993116) was significantly different between T1D and control group (p = 0.040), and the C allele carriers of rs1993116 had a higher risk of T1D than the T allele carriers, Carriers of the CC and CT genotypes of rs1993116 have higher T1D risk than those carrying the TT genotype, the adjusted ORs (and 95% CI) were 2.411(1.194–4.868) and 2.210(1.115–4.377), respectively.