Maternal and neonatal blood vitamin D status and neurodevelopment at 24 months of age: a prospective birth cohort study

Background This study aimed to explore the relationship of 25-hydroxyvitamin D [25(OH)D] in three trimesters and at birth with neurodevelopment at 24 months of age. Methods From 2013 to 2016, pregnant women from the Shanghai Birth Cohort in China were recruited for the study. Altogether, 649 mother-infant pairs were included. Serum 25(OH)D was measured with mass spectrometry in three trimesters, and cord blood was divided into deficiency (< 20 and < 12 ng/mL, respectively), insufficiency (20–30 and 12–20 ng/mL, respectively), and sufficiency (≥ 30 and ≥ 20 ng/mL, respectively). Bayley-III scale was used to assess cognitive, language, motor, social-emotional, and adaptive behavior development at 24 months of age. The Bayley-III scores were grouped into quartiles, and scores within the lowest quartile were defined as suboptimal development. Results After adjusting for confounding factors, cord blood 25(OH)D in the sufficient group was positively correlated with cognitive [ β = 11.43, 95% confidence interval (CI) = 5.65–17.22], language ( β = 6.01, 95% CI = 1.67–10.3), and motor scores ( β = 6.43, 95% CI = 1.73–11.1); cord blood 25(OH)D in the insufficient group was also positively correlated with cognitive scores ( β = 9.42, 95% CI = 3.74–15.11). Additionally, sufficient vitamin D status in the four periods and persistent 25(OH)D ≥ 30 ng/mL throughout pregnancy were associated with a lower risk of suboptimal cognitive development in adjusted models, although the effects were attenuated after applying the false discovery rate adjustment. Conclusions Cord blood 25(OH)D ≥ 12 ng/mL has a significant positive association with cognitive, language, and motor development at 24 months of age. Sufficient vitamin D status in pregnancy might be a protective factor for suboptimal neurocognition development at 24 months of age.