INS and type 1 diabetes mellitus: 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