First-trimester maternal Vitamin D levels and risk for gestational Diabetes mellitus

Abstract

Objectives: Vitamin D deficiency is linked to increased risk of adverse pregnancy outcomes, fetal and neonatal complications, as well as serious health consequences later in life for both mothers and offspring. However, studies on maternal vitamin D status and risk for gestational diabetes mellitus (GDM) are controversial. This study aimed to retrospectively evaluate the risk for GDM based on maternal serum vitamin D levels. Materials and Methods: After applying the exclusion criteria, a total of 197 pregnant women, including 33 GDM cases and 164 controls, were enrolled in the study. Vitamin D levels were measured at 11–14 weeks of gestation. GDM was diagnosed by performing a 75-g oral glucose tolerance test between 24 and 28 weeks of gestation. Results: BMI was higher in the GDM group than in the non-GDM group (24.68 [21.72–27.64] kg/m2 vs. 22.04 [20.51–24.73] kg/m2, p = 0.004). Vitamin D levels were significantly lower in the GDM group than in the non-GDM group (17.2 [15.6–19.2] nmol/L vs. 33.0 [31.2–35.0] nmol/L, p < 0.001). The prevalence of vitamin D deficiency was as high as 87.88% in the GDM group, with a 67.062-fold higher risk for GDM (odds ratio 67.062, 95% confidence interval 20.904–215.150, p < 0.001). Conclusion: Insufficient vitamin D level in early pregnancy is significantly associated with GDM development. Routine screening for vitamin D deficiency during pregnancy, particularly at the first prenatal visit, may contribute to the identification and better management of GDM and its related adverse outcomes in mothers and offspring.