VDR and gestational diabetes: VDR gene FokI rs2228570 TT (TT vs. CC, OR = 3.95, 95% CI: [1.56–9.96], p = 0.002) and CT heterozygotes (CT vs. CC, OR = 1.84, 95% CI: [1.05–3.239, p = 0.031) were associated with having GDM, compared with the controls.