Randomized Trial of Enteral Vitamin D Supplementation in Infants < 28 Weeks Gestational Age or <1000 Grams Birth Weight

The objective of the study is to compare supplementation with vitamin D at 800 IU/day to usual care for the first 28 days after birth with respect to 25 (OH) vitamin D levels and indicators of likely or plausible effects of vitamin D supplementation on the function or structure of the lung, bones, immune system, and brain in extremely premature (EP) infants who are <28 weeks gestational age (GA) or <1000 grams of birth weight (BW). The study results will be analyzed as intention to treat Bayesian analyses (Frequentist analyses will also be performed).

Inclusion Criteria:Infants born at < 28 weeks gestational age (GA) or <1000 grams birth weight (BW)InbornInformed written consent in an Institutional Review Board (IRB)-approved mannerExclusion Criteria:GA >32 weeks regardless of birth weight (BW)Any major congenital anomalyAn overt congenital nonbacterial infectionPrenatal diagnosis of disorders that affect vitamin D absorption (e.g, cystic fibrosis)Such severe illness or immaturity that the attending neonatologist judges intensive care to be unjustified.