title: Effect of vitamin D supplementation on muscle strength, gait and balance in older adults: a systematic review and meta-analysis.
abstract: OBJECTIVE
  To systematically review and quantitatively synthesize the effect of vitamin D supplementation on muscle strength, gait, and balance in older adults.
  
  
  METHODS
  Systematic review and meta-analysis.
  
  
  METHODS
  MEDLINE, EMBASE, Cochrane Library, bibliographies of selected articles, and previous systematic reviews were searched between January 1980 and November 2010 for eligible articles.
  
  
  METHODS
  Older adults (≥60) participating in randomized controlled trials of the effect of supplemental vitamin D without an exercise intervention on muscle strength, gait, and balance.
  
  
  METHODS
  Data were independently extracted, and study quality was evaluated. Meta-analysis using a fixed-effects model was performed and the I(2)  statistic was used to assess heterogeneity.
  
  
  RESULTS
  Of 714 potentially relevant articles, 13 met the inclusion criteria. In the pooled analysis, vitamin D supplementation yielded a standardized mean difference of -0.20 (95% confidence interval (CI) = -0.39 to -0.01, P = .04, I(2)  = 0%) for reduced postural sway, -0.19 (95% CI = -0.35 to -0.02, P = .03, I(2)  = 0%) for decreased time to complete the Timed Up and Go Test, and 0.05 (95% CI = -0.11 to 0.20, P = .04, I(2)  = 0%) for lower extremity strength gain. Regarding dosing frequency regimen, only one study demonstrated a beneficial effect on balance with a single large dose. All studies with daily doses of 800 IU or more demonstrated beneficial effects on balance and muscle strength.
  
  
  CONCLUSIONS
  Supplemental vitamin D with daily doses of 800 to 1,000 IU consistently demonstrated beneficial effects on strength and balance. An effect on gait was not demonstrated, although further evaluation is recommended.
authors.affiliation: Division of Geriatric Medicine, Department of Medicine, Parkwood Hospital, University of Western Ontario, London, Ontario, Canada.
authors.forename: Susan W
authors.initials: SW
authors.lastname: Muir
authors.forename: Manuel
authors.initials: M
authors.lastname: Montero-Odasso
mesh_terms: D000368:Aged; D019587:Dietary Supplements; D005684:Gait / Q000187:drug effects*; D006801:Humans; D008875:Middle Aged; D053580:Muscle Strength / Q000187:drug effects*; D004856:Postural Balance / Q000187:drug effects*; D014807:Vitamin D / Q000008:administration & dosage / Q000627:therapeutic use*
chemical_list: D014807:Vitamin D