Endocrine Abstracts

JOINT633

Background: Vitamin D deficiency is increasingly recognized as a contributor to immune dysregulation and the pathogenesis of pulmonary diseases. Vitamin D plays a pivotal role in alveolar development, and its deficiency—particularly in the neonatal period—may predispose infants to conditions such as bronchopulmonary dysplasia (BPD). This systematic review and meta-analysis aimed to evaluate the association between neonatal vitamin D deficiency and the development of BPD, with secondary outcomes including the incidence of respiratory distress syndrome (RDS), necrotizing enterocolitis (NEC), and mortality before discharge.

Methods: A systematic search of four major databases—Embase, Web of Science, PubMed, and Cochrane—was conducted to identify relevant studies. The primary outcome was the incidence of BPD, while secondary outcomes included the incidences of RDS, NEC, and mortality prior to discharge. Inclusion criteria were studies involving neonates admitted to the neonatal intensive care unit (NICU) with 25-hydroxyvitamin D levels measured at admission and outcomes of interest reported. Studies that lacked data on neonatal vitamin D status or BPD as an outcome measure were excluded. Pooled odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated using a random-effects model to account for heterogeneity among studies.

Results: From a total of 2,298 identified studies, 13 focused on neonatal populations, and 3 met the eligibility criteria. These included two prospective observational studies and one retrospective cohort study. Neonates with vitamin D deficiency had a significantly higher risk of BPD (OR 2.49, 95% CI 1.10–5.68), RDS (OR 2.50, 95% CI 1.21–5.17), and suspected or confirmed NEC (OR 2.55, 95% CI 1.21–5.38) compared to vitamin D-sufficient neonates. No statistically significant difference was observed in mortality before discharge between vitamin D-deficient and -sufficient neonates.

Conclusions: Findings from this systematic review and meta-analysis suggest that 25-hydroxyvitamin D deficiency is an important and potentially modifiable risk factor for the development of BPD, RDS, and NEC in neonates. These results emphasize the need for further research into the mechanistic pathways linking vitamin D deficiency with adverse respiratory and gastrointestinal outcomes in neonates. Additionally, interventional studies evaluating the potential benefits of early vitamin D supplementation in at-risk neonates are warranted. Incorporating routine vitamin D screening into NICU protocols may also help identify vulnerable populations and guide preventive strategies.