Association between vitamin D status at 3 years and eosinophilic asthma in 6-year-old children with a history of severe bronchiolitis.

The association between early childhood serum 25-hydroxyvitamin D (25(OH)D) and eosinophilic asthma remains unclear. We investigated this association using multicentre prospective data from 584 children with a history of bronchiolitis requiring hospitalisation (high-risk population). Low serum 25(OH)D levels (<20 ng/mL) were associated with increased odds of developing eosinophilic asthma (adjusted OR 2.33; 95% CI 1.23, 4.40; p=0.01) as compared with children with serum 25(OH)D of 20-39.9 ng/mL. Our data facilitate further investigation into the potential role of early-life vitamin D supplementation among children with a history of severe bronchiolitis and eosinophilia for preventing childhood asthma.