Females <50 years old (gestational age) had greater prevalence than males.17 VDR polymorphism influences susceptibility to type 1 diabetes mellitus, but association with GDM is not yet clear.18 Vitamin D has suggested to be strongly related to pancreatic β-cell function and insulin sensitivity.8,19 It was reported that, no association was noticed between VDR BsmI polymorphism and GDM in Saudi population.20 This evidence concerns the gene INS and diabetes mellitus.