Vitamin D deficiency and respiratory morbidity among African American very low birth weight infants

Background: Very low birth weight infants (VLBWI) have unexplained variation in respiratory morbidity, including respiratory distress syndrome (RDS) and bronchopulmonary dysplasia (BPD). We examined a potential association to serum 25-hydroxyvitamin D (s-25OHD) on day one. Study design: Prospective, observational study on 89 VLBWI (≤1250 g). S-25OHD (day one and 21) and respiratory severity score (RSS) (day one) were examined. Other respiratory morbidities including BPD were compared between infants with s-25OHD ≤ 10 ng/ml (deficient) versus >10 ng/ml (adequate). Results: Eighty one neonates (91%) were African Americans. The mean (SD) birthweight was 868 (229) g, gestational age 27 (2) weeks. On day one, mean (SD) s-25OHD was 15.48 (8.31) ng/ml, with 32 (37%) being vitamin D deficient. The deficiency and adequate VLBWI groups had similar birthweight; 860 (262) vs 873 (210) g, and gestational age; 27 (2) vs 27 (2) weeks. In 78 survivors, s-25OHD rose from 15.48 (8.31) ng/ml day one to 52.36 (22.49) ng/ml day 21 after supplementation, p < 0.001. On day one, increasing RSS was inversely related to s-25OHD, trend p = 0.054. Compared to the adequate group, the deficiency group had higher RSS (5.0 ± 2.7 vs 3.6 ± 1.9), required surfactant therapy more frequently (91% vs 72%), and needed home oxygen therapy more often (48% vs 26%), p ≤ 0.05 for all. Among infants with BPD, the severity of disease was inversely related to s-25OHD, trend p < 0.09. Conclusion: Lower levels of s-25OHD were associated with increased severity of RDS and BPD among a cohort of mostly African American VLBWI.