Early pregnancy vitamin D insufficiency and gestational diabetes mellitus

Objectives To test the hypothesis that a link existed between vitamin D levels in the first trimester and gestational diabetes mellitus (GDM). Methods The 25-hydroxyvitamin D-3 levels were tested in the first trimester and pregnant outcomes were followed up in 1726 women. Results Only 5.9% of pregnant women have sufficient 25(OH)D-3. More women with GDM are in the status of 25(OH)D-3 insufficiency than women with normal glucose tolerance (NGT) (p < 0.05). Age (odds ratio [OR]: 1.047, 95% confidence interval [CI]: 1.014-1.081), pre-pregnancy body mass index (BMI) (OR: 1.132, 95%CI: 1.092-1.173) were risk factors of GDM while 25-(OH) D-3 (OR: 0.979, 95%CI: 0.960-0.999) was a protective factor. After adjusted for maternal age and pre-pregnancy BMI, 25(OH)D-3 insufficiency (<30 ng/mL) is an independent predictor of GDM (OR: 2.122, 95%CI: 1.084-4.155); 25(OH)D-3 level correlated with fasting blood glucose in the first trimester negatively. Conclusion Vitamin D insufficiency in early pregnancy was significantly associated with an increased risk for GDM in Chinese women.