The present review demonstrates that vitamin D supplementation result ed in small but nonsignificant improvements in muscle strength compared to control in postmenopausal women .
No significant effect was observed in mobility after vitamin D administration
BACKGROUND The results obtained from previous trials regarding the effects of vitamin D supplementation on muscle strength and mobility  in postmenopausal women have been inconsistent .
This systematic review and meta- analysis of r and omised controlled trials ( RCTs ) aim ed to investigate the effect of vitamin D supplementation on muscle strength and mobility in postmenopausal women .
Calcium, vitamin D supplementation, and physical function in the Women's Health Initiative.
OBJECTIVES The Women 's Health Initiative ( WHI ) r and omized trial of calcium/vitamin D supplementation found reduced bone loss with active treatment compared to placebo . Now we examine whether the treatment affected self-reported physical functioning and objective measures of physical functioning . DESIGN A r and omized , double-blind , placebo-controlled trial of 1,000 mg calcium carbonate plus 400 IU vitamin D(3 ) per day or matching placebo pills . SUBJECTS/ SETTING The study included 33,067 women ( 50 to 79 years old ) at 40 US study centers . MAIN OUTCOME MEASURES Physical functioning was assessed by question naire at enrollment in WHI , 1 year prior to calcium/vitamin D trial r and omization and at study close-out ( average follow-up 7.1 years ) . Objective physical performance and self-reported exercise measures were collected at WHI baseline ( 1 year prior to calcium/vitamin D enrollment ) and 2 years and 4 years after calcium/vitamin D trial enrollment in a sub sample ( n=3,137 ) . STATISTICAL ANALYSES PERFORMED Calcium/vitamin D effects were tested in unadjusted and interaction linear models for each of the physical function measures . Covariates were baseline total calcium intake , fracture risk score , treatment arm in the hormone therapy and dietary modification trials ( ie , active drug or placebo , low-fat diet intervention or usual diet , respectively ) and age . RESULTS Neither intention to treat nor high adherence analyses produced substantial effects of calcium/vitamin D  compared to placebo on physical functioning or performance . The interaction analyses also did not result in differences because of calcium/vitamin D. CONCLUSIONS As the first long-term r and omized trial to examine the effectiveness of calcium and vitamin D in protecting against decline of physical functioning in older women , the results did not support benefit
The present review demonstrates that vitamin D supplementation result ed in small but nonsignificant improvements in muscle strength compared to control in postmenopausal women .
No significant effect was observed in mobility after vitamin D administration
BACKGROUND The results obtained from previous trials regarding the effects of vitamin D supplementation on muscle strength and mobility  in postmenopausal women have been inconsistent .
This systematic review and meta- analysis of r and omised controlled trials ( RCTs ) aim ed to investigate the effect of vitamin D supplementation on muscle strength and mobility in postmenopausal women .