In conclusion , we observed no improvement in muscle strength after the administration of vitamin D with or without calcium supplements .
We did find a small but significant deterioration of mobility .
BACKGROUND It has been suggested that vitamin D status or supplementation is important for maintaining or improving muscle strength and mobility in older adults .
The study results , however , do not provide consistent results .
We therefore aim ed to summarise the available evidence systematic ally , including only studies conducted in community-dwelling older persons .
A randomized controlled trial of the effects of vitamin D on muscle strength and mobility in older women with vitamin D insufficiency.
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 , r and omized , 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 D(2 ) 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 ± st and ard 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 ( st and ard 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
In conclusion , we observed no improvement in muscle strength after the administration of vitamin D with or without calcium supplements .
We did find a small but significant deterioration of mobility .
BACKGROUND It has been suggested that vitamin D status or supplementation is important for maintaining or improving muscle strength and mobility in older adults .
The study results , however , do not provide consistent results .
We therefore aim ed to summarise the available evidence systematic ally , including only studies conducted in community-dwelling older persons .