Vitamin D Deficiency Is Associated with Pulmonary Exacerbations in Children with Cystic Fibrosis

Rationale: Recent literature suggests vitamin D has an effect on lung function and on the lung’s ability to fight infection, both important in the cystic fibrosis (CF) population as predictors of morbidity and mortality. Objectives: Our study assessed associations between vitamin D and % predicted lung function, pulmonary exacerbations, and first Pseudomonas aeruginosa infection in children with CF. We hypothesized that children with CF who have 25-hydroxy vitamin D (25-OHD) levels less than 30 μg/L would have lower % predicted lung function and more pulmonary exacerbations than those with 25-OHD greater than or equal to 30 μg/L. Methods: This retrospective longitudinal study of 130 children aged 6 to 18 years between 2000 and 2012 examined 25-OHD levels classed in three vitamin D groups: sufficient (≥30 μg/L), insufficient (20–29 μg/L), and deficient (