Supplemental vitamin D and physical performance in COPD: a pilot randomized trial
What this study found
Vitamin D supplementation increased serum 25(OH)D but did not improve physical performance or health-related quality of life over 6 weeks. The primary outcome, SPPB change, did not differ meaningfully between groups: 0.3 points for vitamin D minus placebo, 95% CI -0.8 to 1.5; p = 0.56. Serum 25(OH)D rose by 8.7 ± 5.5 ng/mL in the vitamin D arm versus -1.8 ± 3.1 ng/mL in placebo, for a between-group difference of 10.5 (7.43 to 13.61). SGRQ change also showed no clear benefit. No study-related serious adverse events occurred in either arm.
- Study & population
- Pilot randomized, placebo-controlled trial in adults with severe COPD recruited from the Minneapolis Veterans Affairs Health Care System.
- Intervention
- For the vitamin D group, participants received cholecalciferol 2000 IU/day as an oral capsule once daily for 6 weeks, compared with placebo.
- Key limitation
- This was a small pilot trial with only 18 completers in the vitamin D arm and a short 6-week duration, limiting power to detect clinical benefit.
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Open PDFOriginal 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). 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.