Abstract 077: Effect of Vitamin D Supplementation on Cardiovascular Health in Pregnant Women and Offspring Based on the Gestational Diabetes Mellitus Status

Aims Women with gestational diabetes mellitus (GDM) are at increased risk for impaired cardiovascular health (CVH) during pregnancy and may face a higher likelihood of cardiovascular disease (CVD) later in life. Our study explored the possible protective effects of vitamin D supplementation on cardiovascular health in pregnant women and offspring, focusing on GDM status. Methods and Results We randomly assigned women with a serum 25-hydroxyvitamin D concentration <75 nmol/L during gestational weeks 24-28 to receive 1200 IU/d of vitamin D 3 or the recommended 400-600 IU/d for two months. These groups were subdivided based on their GDM status: vitamin D + GDM, vitamin D + non-GDM, control + GDM, and control + non-GDM. There were 1563 participants. Women in the vitamin D + GDM group had lower concentrations of total cholesterol (mean difference with 95 % confidence interval [CI]: [-0.38 (-0.64, -0.12) mmol/L]), triglycerides [-0.34 (-0.61, -0.09) mmol/L], hypersensitive C-reactive protein [-0.82 (-1.55, -0.10) mg/L], and systolic blood pressure [-1.97 (-3.66, -0.14) mm Hg] than the control + GDM group after supplementation. Women in the vitamin D + GDM group had less severe gestational CVH than those in the control + GDM group, indicated by the gestational CVH score, the number of women with all “ideal” CVH metrics, and the mean ten-year atherosclerotic cardiovascular disease risk prediction ( P < 0.05). The macrosomia prevalence and the cord blood hypersensitive C-reactive protein concentration were significantly decreased in the vitamin D + GDM group. Conclusion: Vitamin D supplementation during pregnancy might improve CVH in women with GDM and their offspring, which is beneficial for the primary prevention of CVD later in life.