Associations between vitamin D levels and glucose metabolism markers among pregnant women and their infants in Puerto Rico

Objectives: low vitamin D during pregnancy is common and could adversely affect health outcomes. This study evaluated vitamin D status during pregnancy and early in life, and its association with glucose metabolism. Methods: maternal serum 25(OH)D, glucose, and insulin levels were measured longitudinally during pregnancy in Hispanic women with overweight/obesity (n = 31) and their infants at birth and 4 months. Results: insulin and HOMA-IR levels were higher among women with vitamin D below adequate levels compared to those with adequate levels in pregnancy (p < 0.05). Late in pregnancy, as vitamin D increased by one unit (ng/mL), insulin decreased by 0.44 units and HOMA-IR by 0.09 units. Maternal vitamin D late in pregnancy was correlated with infant vitamin D levels at birth (r = 0.89; p < 0.01) and 4 months (r = 0.9; p = 0.04), and with glucose (r = 0.79; p = 0.03) and insulin (r = 0.83; p = 0.04) at 4 months. Conclusion: maternal vitamin D status was associated with maternal and infant glucose metabolism in this sample.