Effect of vitamin D supplementation on incidence of bronchopulmonary dysplasia among preterm infants up to 36 weeks' gestational age.

Preterm infants, especially those born at a younger gestational age (GA), are at risk for developing bronchopulmonary dysplasia (BPD), which can lead to longer hospitalizations, chronic pulmonary morbidity, and mortality. Vitamin D plays a role in lung and immune system development, and deficiency at birth is associated with a greater incidence of BPD among preterm infants. The purpose of this literature review was to determine the impact of vitamin D supplementation on BPD incidence among preterm infants born ≤36 weeks GA. A literature search of the PubMed, CINAHL, SCOPUS, and Google Scholar databases was conducted searching for clinical studies published since 2014 that evaluated the effect of vitamin D supplementation on BPD incidence among preterm infants ≤36 weeks GA. We identified and reviewed six clinical studies published between 2014 and 2023, including a total of 545 preterm infants born 25-34 weeks GA. Vitamin D supplementation between 800-1000 IU/day was safe and effective in significantly improving vitamin D status and significantly reducing vitamin D deficiency; however, positive findings regarding the influence of vitamin D supplementation in reducing the incidence of BPD were not consistent. More research is needed in the form of well-designed RCTs investigating the effect of vitamin D supplemented at 800-1000 IU compared with the standard 400 IU dose on the incidence of BPD as the primary outcome.