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

Objective To evaluate the relationship between vitamin D receptor (VDR) gene polymorphism (Fokl [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 Fokl. 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 serum vitamin 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 Fokl genotypic frequency when the 2 groups were compared with each other (p = 0.41). Conclusion There was no association between the Fold polymorphism and the development of GDM, nor was there any change in serum vitamin D levels in patients with GDM.