The effect of vitamin D supplementation on lower-extremity power and function in older adults: a randomized controlled trial. Issue 2 (1st February 2019)

• Record Type: Journal Article
• Authors: Shea, M Kyla; Fielding, Roger A; Dawson-Hughes, Bess
• Is Part Of: American journal of clinical nutrition. Volume 109:Issue 2(2019)
• Page Start: 369
• Page End: 379
• Publication Date: 2019-02-01
• Subjects: vitamin D -- physical function -- muscle -- clinical trial -- older adults; Diet therapy -- Periodicals; Nutrition -- Periodicals; Dietetics -- Periodicals; 613.205
• DOI: 10.1093/ajcn/nqy290
• Languages: English
• ISSNs: 0002-9165

Abstract

ABSTRACT: Background: The effect of vitamin D supplementation on muscle function in older adults has been tested in randomized trials with mixed results, which may be due to differences in the study participant characteristics, including baseline vitamin D status. The results of 2 meta-analyses of randomized trials suggested a beneficial effect of vitamin D supplementation on muscle function in older adults with low baseline serum 25-hydroxyvitamin D [25(OH)D]. Objectives: We aimed to test the effect of 12 mo of vitamin D supplementation on lower-extremity power and function in older community-dwelling adults screened for low serum 25(OH)D. Methods: This was a single-center, double-blind, randomized, placebo-controlled trial that included 100 community-dwelling men and women ≥60 y old who had serum 25(OH)D ≤20 ng/mL at screening and a mean ± SD serum 25(OH)D of 20.2 ± 6.7 ng/mL at baseline. Participants were randomly assigned to 800 IU vitamin D3 /d (intervention) or placebo. Those in the intervention group whose serum 25(OH)D was <28 ng/mL after 4 mo were given an additional 800 IU vitamin D3 /d, whereas all other participants received placebo as an additional pill. Results: After 12 mo, the mean ± SD serum 25(OH)D was 32.5 ± 5.1 ng/mL in the intervention group and 19.8 ± 7.3 ng/mL in the control group (treatment × time P < 0.001). The change in leg press power, function, and strength did not differ between the 2 groups over 12 mo (all treatment × time P ≥ 0.60), nor did the change in lean mass (treatment × time P ≥ 0.89). Conclusion: Increasing serum 25(OH)D to >32 ng/mL (on average) over 12 mo did not affect lower-extremity power, strength, or lean mass in older community-dwelling adults. This trial was registered at clinicaltrials.gov as NCT02293187.