Background/objectives: To determine the association between cord blood 25-hydroxyvitamin D (25(OH)D) concentration with growth, adiposity and neurodevelopment during infancy.
Subjects/methods: Serum 25(OH)D was measured in cord blood by the liquid chromatography tandem mass spectrometry (LC-MS/MS) from the Shanghai's "Allergy and Obesity Cohort study" (n = 1244). Weight, length, head circumference, and body mass index (BMI) z-scores for age were calculated based on World Health Organization Standard (at 6 months, 1 years, and 2 years). Neurodevelopment was measured at 2 years using Ages and Stages Questionnaire. Generalized estimating equation and multivariable logistic regression model were exploited to examine associations between fetal 25(OH)D concentration and offspring outcomes.
Results: The median of the 25(OH)D concentration in cord blood was 22.4 ng/ml (interquartile range, 27.3-8.6). Infants born in winter had lower 25(OH)D concentration. 25(OH)D deficiency was not associated with weight z-score (mean difference, 0.07; 95% confidence internal (CI), -0.09 to 0.23), length z-score (mean difference, 0.01; 95% CI, -0.19 to 0.21), head circumference z-score (mean difference, -0.06; 95% CI, -0.27 to 0.15) and BMI z-score (mean difference, 0.09; 95% CI, -0.07 to 0.25) or neurodevelopment during infancy, adjusting for sex, socio-economic position, pre-pregnancy maternal BMI, and maternal and neonatal characteristics. The associations did not vary by gender. A sensitivity analysis of available case analysis showed virtually the same results.
Conclusions: Fetal vitamin D concentration was not associated with growth, adiposity or neurodevelopment during infancy. The role of vitamin D concentration and its mechanistic pathway in the early origins of adiposity needs to be clarified.