title: Supplemental vitamin D and physical performance in COPD: a pilot randomized trial.
abstract: 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).
  
  
  CONCLUSIONS
  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.
authors: University of Minnesota, Minneapolis, MN, USA.
authors: Sonja M
authors: SM
authors: Bjerk
authors: Bradley D
authors: BD
authors: Edgington
authors: Thomas S
authors: TS
authors: Rector
authors: Ken M
authors: KM
authors: Kunisaki
mesh_terms: D000368:Aged; D002762:Cholecalciferol / Q000627:therapeutic use*; D005080:Exercise Test; D005684:Gait / Q000502:physiology; D006801:Humans; D016014:Linear Models; D008297:Male; D053580:Muscle Strength / Q000502:physiology; D010865:Pilot Projects; D004856:Postural Balance / Q000502:physiology; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy* / Q000503:physiopathology; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014815:Vitamins / Q000627:therapeutic use*
chemical_list: D014815:Vitamins; D014807:Vitamin D; D002762:Cholecalciferol; C104450:25-hydroxyvitamin D
keywords: chronic obstructive pulmonary disease; randomized controlled trial; skeletal muscle strength; vitamin D