Impact of vitamin D on spirometry findings and quality of life in patients with chronic obstructive pulmonary disease: a randomized, double-blinded, placebo-controlled clinical trial

COPD is an irreversible chronic illness with airflow limitation. The aim of the current study was to assess the role of vitamin D on quality of life and pulmonary function in patients with COPD. A randomized, double-blinded clinical trial was conducted in 63 patients with COPD. Patients were placed into intervention and placebo groups. Each individual in the intervention group took 50,000 IU vitamin D once a week for 8 weeks and then once a month for 4 months. There was no significant difference among FEV , FEV /FVC, and number of exacerbations in patients with COPD ( >0.05). In the intervention group, a significant difference was observed in quality of life at 2 months (