Hypovitaminosis D in patients with cystic fibrosis: a cross-section study in South Brazil.

Introduction: Cystic fibrosis (CF) patients have a susceptibility to vitamin D deficiency because of nutrient malabsorption.

Objectives: To evaluate the prevalence of hypovitaminosis D in CF patients and the factors associated with serum 25-hydroxyvitamin D levels.

Methods: We evaluated the prevalence of vitamin D deficiency defined as 25-hydroxyvitamin D <30 ng/mL, as suggested recently by the Cystic Fibrosis Foundation, and factors associated with its serum levels.