Do vitamin D levels affect forced expiratory flow 25–75 among children with asthma?

This cross-sectional study examined the correlation between serum vitamin D levels and pulmonary function parameters in 50 children aged 6–12 years with a diagnosis of asthma. Lung function parameters examined in the study, which included FEV1, FVC, FEV1/FVC ratio, FEF25–75, and PEF, were measured using a Vitalograph Alpha spirometer.