No association between type 1 diabetes and genetic variation in vitamin D metabolism genes: a Danish study.

ABSTRACT

BACKGROUND: Vitamin D, certain single nucleotide polymorphisms (SNPs) in the vitamin D-receptor (VDR) gene and vitamin D metabolism genes have been associated with type 1 diabetes (T1D). OBJECTIVE: We wanted to examine if the most widely studied SNPs in genes important for production, transport, and action of vitamin D were associated with T1D or to circulating levels of vitamin D 25-hydroxyvitamin D [25(OH)D] in a juvenile Danish population. METHODS: We genotyped eight SNPs in five vitamin D metabolism genes in 1467 trios. 25(OH)D status were analyzed in 1803 children (907 patients and 896 siblings). RESULTS: We did not demonstrate association with T1D for SNPs in the following genes CYP27B1, VDR, GC, CYP2R1, DHCR7, and CYP24A1. Though, variants in the GC gene were significantly associated with 25(OH)D levels in the joint model. CONCLUSION: Some of the most examined SNPs in vitamin D metabolism genes were not confirmed to be associated with T1D, though 25(OH) levels were associated with variants in the GC gene.