DHCR7 and type 1 diabetes mellitus: Recently, Zhang et al., 2012 have linked some of the DHCR7/NADSYN1 SNPs (rs3829251, rs12785878) to decreased serum 25(OH)D levels in northeastern Han Chinese children [24], while Cooper et al., 2011 has associated rs12785878 T allele carriers with vitamin D deficiency and type 1 diabetes [32].