Cholecalciferol Supplementation in Strengthening Inspiratory Muscles in Cholecalciferol-Deficient Patients With Chronic Obstructive Pulmonary Disease

PRIMARY OBJECTIVES: I. To establish the effect of D vitamin (vitamin D3) supplementation on inspiratory muscle strength in vitamin D3-deficient chronic obstructive pulmonary disease (COPD) patients. (Roswell Park Cancer Institute \[RPCI\]/University at Buffalo \[UB\] study) II. To establish the 12 month conversion rate. (University of Pittsburgh Cancer Institute \[UPCI\] study) SECONDARY OBJECTIVES: I. To establish the effect of vitamin D3 supplementation on peripheral muscle strength and exercise capacity in vitamin D3-deficient COPD patients. (RPCI/UB study) II. To establish the 3 and 6-month conversion rates. (UPCI study) III. To examine whether vitamin D3 supplementation is equally effective in COPD patients who are current versus former smokers. (UPCI study) TERTIARY OBJECTIVES: I. To explore the effects of vitamin D3 supplementation in COPD patients on biomarkers of lung cancer risk, inflammation, and pulmonary function. (UPCI study) OUTLINE: Patients are randomized to 1 of 2 arms. CONTROL ARM: Patients receive a placebo and multivitamin orally (PO) once daily (QD) for 52 weeks. SUPPLEMENTATION ARM: Patients receive a multivitamin and cholecalciferol supplement PO QD for 52 weeks. After completion of study treatment, patients are followed up for 1 year.