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.