Multiple loci in VD signaling pathways (CYP27A1, CYP27B1, CYP24A1, VDR, RXR and GC genes) were found to be associated with vitamin D levels [16], so it is plausible that common variants in these genes that influence vitamin D level could predispose to GDM. This evidence concerns the gene CYP27B1 and gestational diabetes.