(P10-089-24) The Effect of Vitamin D Supplementation on the Risk of Gestational Diabetes in Pregnant Women Over the Age of 18 Without a Diabetes or Gestational Diabetes Diagnosis

Objectives: To assess the effectiveness of vitamin D supplementation during pregnancy on GDM incidence in adult women without diabetes or GDM diagnosis.

Methods: A literature search was conducted through PubMed, CINAHL, Web of Science, and EBSCOhost. Key terms included: “vitamin D supplementation,” “pregnant women,” and “GDM incidence.” Randomized controlled trials (RCT) published between 2013-2023 assessing vitamin D supplementation compared to placebo in adult pregnant women on GDM incidence were reviewed resulting in 756 articles with 4 RCTs meeting the inclusion criteria.

Results: All RCTs were conducted outside the U.S. and assessed vitamin D supplementation compared to placebo. Baseline serum vitamin D status varied across studies from deficient to sufficient. Each article contained varying dosages and frequencies of supplementation, which ranged from 1,600 IU to 4,000 IU/day, while one provided 50,000 IU biweekly. After intervention, only one article found a statistically significant effect on GDM incidence (p=0.009). However, two articles found supplementation significantly improved baseline vitamin D levels and fasting blood glucose when compared within groups.

Conclusions: Further research is required to determine the effects of vitamin D supplementation on GDM incidence regardless of vitamin D status. However, vitamin D supplementation appears safe and aids in repletion if needed.

Funding Sources: N/A