The Department of Neonatology, Zhengzhou Children's Hospital

Bronchopulmonary dysplasia (BPD) is the most prevalent longterm morbidity among surviving extremely preterm infants and has a multifactorial etiology. BPD is associated with later risk of reactive airways disease, such as asthma, post neonatal mortality and adverse neurodevelopmental outcomes.Retinopathy of prematurity (ROP) is a common retinal neovascular disorder and a major cause of vision impairment or blindness in preterm infants, even with aggressed current standard care.Accumulating epidemiologic evidence suggests that vitamin D (VD) deficiency or insufficiency is associated with respiratory disease and metabolic bone disease in premature children.Vitamin A (VA) plays an integral part in lung growth and differentiation. VA is an essential micronutrient for normal visual function.

Our prospective double-blinded randomized controlled trial will include infants born at <32 weeks' gestation and admitted to six tertiary NICUs in China. Infants in the intervention (vitamin AD drops) group will receive the daily dose VA at 1500 IU/day with VD 500 IU/day, added to their enteral feeds in drop form as soon as minimal feeding was introduced, and continued to 28 days or discharge. Infants in the control group will receive an equivalent volume of a placebo solution. Following informed consent, enrolled infants will be randomly allocated to the control or VAD group. The primary outcome is bronchopulmonary dysplasia (BPD) , ROP, or metabolic bone disease and the secondary outcomes are mortality; NEC ≥ stage 2; ; late-onset sepsis; weight gain, change in weight, increase in length, increase in head circumference; time to full enteral feeds; and number and type of critical incident reports.