Association between serum 25 (OH) vitamin D level at birth and respiratory morbidities among preterm neonates.

OBJECTIVES: To determine the association between 25-hydroxyvitamin D [25(OH)D] levels on first day of life with respiratory distress syndrome (RDS), need and duration of mechanical ventilation, and subsequent development of bronchopulmonary dysplasia (BPD) among preterm neonates.

STUDY DESIGN: In this case-control study, serum 25(OH)D was measured on first day of life in 65 preterm neonates <34 weeks: 40 with RDS and 25 without RDS and compared between them. Serum 25(OH)D levels were categorized into normal (above 30 ng/ml), insufficiency (20-30 ng/ml), moderate deficiency (10-20 ng/ml), and severe deficiency (<10 ng/ml). Neonates with different 25(OH)D levels were compared as regard grade of RDS, initial pH, initial CO2 , need and duration of mechanical ventilation, development of BPD, and mortality.

RESULTS: Only one of 65 studied preterm neonates had normal vitamin D level. Neonates with RDS had significantly lower mean serum 25(OH)D level than controls (10.6 versus 13.9 ng/dl) (p = .028). Neonates with severe 25(OH)D deficiency developed more BPD than those with moderate deficiency (29.4 versus 8.7%) but did not reach significant level (p value = .08). There is no correlation between serum 25(OH)D level and duration of mechanical ventilation. Logistic regression analysis shows that low serum 25(OH)D level is an independent risk factor for RDS.

CONCLUSION: Low 25(OH)D level is far frequent among Egyptian preterm neonates. Vitamin D deficiency is an independent risk factor for development of RDS in preterm neonates.