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A randomized controlled trial of the effects of vitamin D on muscle strength and mobility in older women with vitamin D insufficiency

journal contribution
posted on 2010-11-01, 00:00 authored by K Zhu, Nicole Austin, A Devine, D Bruce, R L Prince
OBJECTIVES: To evaluate the effects of vitamin D treatment on muscle strength and mobility in older women with vitamin D insufficiency.

DESIGN: One-year population-based, double-blind, randomized, controlled trial.

SETTING: Perth, Australia (latitude 32°S).

PARTICIPANTS: Three hundred two community-dwelling ambulant elderly women aged 70 to 90 with a serum 25-hydroxyvitamin D (25(OH)D) concentration less than 24 ng/mL.

INTERVENTION: Vitamin D2 1,000 IU/d or identical placebo; calcium citrate (1 g calcium/d) in both groups.

MEASUREMENTS: Lower limb muscle strength and mobility as assessed using the Timed Up and Go Test (TUAG).

RESULTS: At baseline, mean±standard deviation serum 25(OH)D was 17.7±4.2 ng/mL; this increased to 24.0±5.6 ng/mL in the vitamin D group after 1 year but remained the same in the placebo group. For hip extensor and adductor strength and TUAG, but not for other muscle groups, a significant interaction between treatment group and baseline values was noted. In those with baseline values in the lowest tertile, vitamin D improved muscle strength and TUAG more than calcium alone (mean (standard error): hip extensors 22.6% (9.5%); hip adductors 13.5% (6.7%), TUAG 17.5% (7.6%), P<.05). Baseline 25(OH)D levels did not influence patient response to supplementation.

CONCLUSION: Vitamin D therapy was observed to increase muscle function in those who were the weakest and slowest at baseline. Vitamin D should be given to people with insufficiency or deficiency to improve muscle strength and mobility.

History

Journal

Journal of the American Geriatrics Society

Volume

58

Issue

11

Pagination

2063 - 2068

Publisher

Wiley

Location

Malden, Mass.

ISSN

0002-8614

eISSN

1532-5415

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

2010, The Authors