Background An adequate maternal vitamin D (vitD) intake is rarely achieved in actual practice. The aim of this study was to assess maternal factors associated with neonatal vitD deficiency. Methods This is a single-institution prospective case-control study. Consecutive single-birth neonates admitted between September 2014 and February 2015 were prospectively enrolled. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were measured by spectrometry. The associations between neonatal vitD deficiency (defined as 25(OH)D <15 ng/mL) and several maternal characteristics, including body mass index (BMI) at delivery, education, health insurance status, birth season, sun exposure time, egg consumption, and vitD supplementation during pregnancy, were examined using multivariable logistic regression and their respective odds ratios (ORs) reported. Results A total of 125 mother-infant dyads were enrolled, with a gestational age of 36.8±2.7 weeks. Fifty-six percent (70/125) of the neonates had vitD deficiency. Maternal factors that were significantly associated with vitD deficiency included winter birth, insufficient sun exposure time, high maternal BMI at delivery, insufficient egg consumption, insufficient vitD supplementation during pregnancy, and disadvantaged health insurance. Disadvantaged insurance status and insufficient vitD supplementation during pregnancy were the two most influential factors of neonatal vitD deficiency, with an OR of 7.5 (95% confidence interval [CI], 2.0-37.6) and 7.0 (95% CI, 2.7-20.7), respectively. Conclusions Neonatal vitD deficiency is very rampant. An individualized vitD supplementation strategy may be developed by taking into consideration pregnant women's socioeconomic status and lifestyles.
Keywords: associated factors; infant; neonate; pregnant woman; vitamin D deficiency.