Maternal vitamin D deficiency increases the risk of adverse neonatal outcomes in the Chinese population: A prospective cohort study

Background Although vitamin D (vitD) deficiency is a common problem in pregnant women, in China, few studies have focused on the relationship between maternal vitD deficiency throughout the three trimesters and subsequent neonatal outcomes in China. Methods Between 2015 and 2016, maternal serum and neonate cord blood samples were collected from 1978 mother-neonate pairs from Liuzhou city. Results The mean concentrations of 25-hydroxy vitD (25(OH) D) were 16.17 +/- 6.27 and 15.23 +/- 5.43 ng/ml in the mother and neonate groups, respectively, and the prevalence values of vitD deficiency in the two groups were 78.18% and 83.27%, respectively. Logistic regression showed that maternal vitD deficiency independently increased the risk of gestational diabetes mellitus (GDM) (adjust OR, aOR 1.08; P = 0.026). A relatively lower risk of vitD deficiency was observed in the third trimester than in the first and second trimester (aOR 0.80; P = 0.004). VitD-calcium cosupplementation during pregnancy improves the vitD deficiency in both the maternal and neonatal groups (aOR 0.56, 0.66; P<0.001 and 0.021, respectively). Maternal vitD deficiency significantly increased the risk of neonatal low birth weight (LBW) (aOR 2.83; P = 0.005) and small-for-gestational-age (SGA) (aOR 1.17; P = 0.015). There was a positive correlation between maternal and neonatal vitD deficiency (r = 0.879, P<0.001). VitD supplementation during pregnancy significantly reduced the risk of giving birth to LBW infants (OR = 0.47, 95% CI = 0.33-0.68, P<0.001). Conclusions Further research focusing on the consumption of vitD with calcium during pregnancy and the consequential clinical outcomes in Chinese pregnant women is warranted.