Journal of Diabetes and Metabolic Disorders50RELATIONSHIP BETWEEN VITAMIN D DEFICIENCY AND GESTATIONAL DIABETES MELLITUS.151151ArashHossein-NezhadJilaMaghbooliSeyed MasoudArzaghiAlirezaShafaeiMazaherRahmaniBagherLarijani20151005Background: Although there is increasing evidences that vitamin D is related to the occurrence of diabetes mellitus, its relation to glucose metabolism in pregnancy is not well studied. This study investigated 25-hydroxyvitamin D deficiency status in GDM pregnant women. Methods: As a cross sectional study we recruited 741 pregnant women referred to five university educating hospital clinics. The universal screening was performed with a GCT-50g and those with plasma glucose level ≥130mg/dl, were diagnosed as GDM, if they had an impaired GTT-100g based on Carpenter and Coustan criteria. The levels of insulin was studied during OGTT-100g. Serum concentrations of 25-hydroxy vitamin D was measured too. Results: Univeriate analysis revealed that 25 (OH) vit D concentrations were positively correlated with HOMA and ISOGTT index. Subjects with hypovitaminosis D (<12.5nmol/dl) had greater prevalence of GDM than others. Conclusion: The results reveal a positive association between 25(OH) vit D concentrations and insulin sensitivity. Vit D deficiency is more prevalent in patients with GDM than normal pregnant women, So vit D supplementation may control glucose levels and improves outcome of pregnancy.https://jdmd.tums.ac.ir/index.php/jdmd/article/view/151