Assessment of Polymorphismof the VDR Gene and Serum Vitamin D Values in Gestational Diabetes Mellitus

Abstract Objective To evaluate the relationship between vitamin D receptor (VDR) gene polymorphism (FokI [rs10735810]) and serum vitamin D concentration in gestational diabetes mellitus (GDM). Methods A prospective case-control study that recruited healthy pregnant women (control group) (n = 78) and women with GDM (GDM group) (n = 79), with no other comorbidities. Peripheral blood samples were collected in the 3rd trimester of gestation, and all of the pregnant women were followed-up until the end of the pregnancy and the postpartum period. Serum vitamin D concentrations were measured by high-performance liquid chromatography (HPLC). For genomic polymorphism analysis, the genomic DNA was extracted by the dodecyltrimethylammonium bromide/ cetyltrimethylammonium bromide (DTAB/CTAB) method, and genotyping was performed by the polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) technique, using the restriction enzyme FokI. The Student-t, Mann- Whitney, chi-squared, and Fischer exact tests were used for the analysis of the results. Results There was no significant difference between the pregnant women in the control and GDM groups regarding serumvitamin D levels (17.60 ± 8.89 ng/mL versus 23.60 ± 10.68 ng/mL; p = 0.1). Also, no significant difference was detected between the FokI genotypic frequency when the 2 groups were compared with each other (p = 0.41). Conclusion There was no association between the FokI polymorphism and the development of GDM, nor was there any change in serum vitamin D levels in patients with GDM.