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 CO, 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.