Vitamin D and associated perinatal-neonatal outcomes among extremely low-birth-weight infants

Objective To evaluate vitamin D inadequacy among extremely low-birth-weight (ELBW, <1000 g) infants and the association between circulating vitamin D concentrations and perinatal-neonatal outcomes. Study design Prospective cohort study of ELBW infants in the neonatal ICU. Blood was collected within the first 3 days after birth after obtaining informed consent. Circulating 25-hydroxyvitamin D concentrations (25(OH)D) were quantified using liquid chromatography-tandem mass spectroscopy and classified as vitamin D deficient, insufficient, or adequate ( < 20, 20-30, or > 30 ng/mL, respectively). Associations between 25(OH)D and perinatal-neonatal outcomes were determined by multivariable regression, adjusted for covariates that differ in the bivariate analysis. Results Of the 60 ELBW infants enrolled, 13 (22%) were vitamin D deficient, 15 (25%) were insufficient, and 32 (53%) were adequate. 25(OH)D levels were positively associated with fetal growth restriction and prolonged rupture of the membranes. Conclusions Vitamin D inadequacy was frequent among ELBW infants. Circulating vitamin D concentrations were significantly associated with perinatal outcomes in this contemporary cohort.