Association of Gestational Diabetes Mellitus with Vitamin D Levels and Various Demographic Factors: A Cross-sectional Study at a Tertiary Care Hospital

Introduction Existing evidence suggests an inconsistent association between maternal serum vitamin D levels and the risk of gestational diabetes mellitus (GDM). The present study aims to identify factors associated with the development of GDM in pregnant women and to evaluate its association with maternal vitamin D levels. Methods This cross-sectional analysis included 100 women with singleton pregnancies, comprising 50 diagnosed with GDM and 50 normoglycemic controls. Serum 25-hydroxyvitamin D [25(OH)D] levels were assessed in all participants during the 24- to 28-week gestational period. Results Analysis of the two groups (50 cases and 50 controls) revealed that only 11% of pregnant women had adequate vitamin D levels, while 22% had insufficiency, and 67% had deficiency. The study found a significant association of GDM with age ( P < .01), family history of diabetes ( P < .01), body mass index (BMI) ( P = .01), and physical inactivity ( P = .03). However, there was no significant difference in mean [25(OH)D] level between women with GDM and the control group ( P = .05). Also, no significant correlation was observed between vitamin D levels and oral glucose tolerance test (OGTT) values ( r value = −0.12, P = .21). Conclusion The study showed a high prevalence of vitamin D deficiency in pregnant women, despite adequate sunlight exposure in a tropical region. GDM was significantly associated with age, family history, physical inactivity, and BMI. However, no significant association was observed between vitamin D levels and GDM. These findings highlight the need for well-designed, large-scale multicenter studies to further clarify this association.