Supplemental vitamin D and physical performance in COPD: a pilot randomized trial

pplemental vitamin D and physical performance in COPD: a pilot randomized trial Original Research (1104) Total Article Views Authors: Bjerk SM, Edgington BD, Rector TS, Kunisaki KM Published Date February 2013 Volume 2013:8 Pages 97 - 104 DOI: http://dx.doi.org/10.2147/COPD.S40885 Received: 29 November 2012 Accepted: 11 January 2013 Published: 15 February 2013 Sonja M Bjerk,1 Bradley D Edgington,1 Thomas S Rector,1,2 Ken M Kunisaki1,2 1University of Minnesota, 2Minneapolis VA Health Care System, Minneapolis, MN, USA Background: Low 25-hydroxyvitamin D (25[OH]D) levels, commonly observed in chronic obstructive pulmonary disease (COPD), are associated with muscle weakness in elderly populations, and vitamin D supplementation appears to improve muscle strength and decrease falls in older individuals. We tested the effect of vitamin D supplementation on physical performance in patients with COPD. Methods: Patients were randomized to daily cholecalciferol (2000 IU) or placebo for 6 weeks. The primary outcome was the 6-week change in Short Physical Performance Battery (SPPB) score. Secondary outcomes included changes in the St George’s Respiratory Questionnaire (SGRQ) score, and serum 25(OH)D. Results: Thirty-six participants (mean age 68 years, all Caucasian males, mean forced expiratory volume in one second 33% of predicted) completed the study. Despite an increase in 25(OH)D levels in the intervention arm to a mean of 32.6 ng/mL (versus 22.1 ng/mL in the placebo arm), there was no difference in improvements in either SPPB scores (0.3 point difference; 95% confidence interval -0.8 to 1.5; P = 0.56) or SGRQ scores (2.3 point difference; 95% confidence interval -2.3 to 6.9; P = 0.32). Conclusion: Among patients with severe COPD, 2000 IU of daily vitamin D for 6 weeks increased 25(OH)D to a level widely considered as normal. However, compared with placebo, short-term vitamin D supplementation had no discernible effect on a simple measure of physical performance.