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 .
Once-weekly dose of 8400 IU vitamin D(3) compared with placebo: effects on neuromuscular function and tolerability in older adults with vitamin D insufficiency.
BACKGROUND Vitamin D insufficiency , which is prevalent in older individuals , is associated with bone and muscle weakness and falls . OBJECTIVE We examined the effects of a weekly dose of 8400 IU vitamin D(3 ) on postural stability , muscle strength , and safety . DESIGN In this double-blind trial , subjects aged > or = 70 y with serum 25-hydroxyvitamin D [ 25(OH)D ] concentrations < or = 20 but > or = 6 ng/mL were r and omly assigned to receive a weekly dose of 8400 IU  vitamin D(3 ) ( n = 114 ) or a placebo ( n = 112 ) . Mediolateral body sway with eyes open ( assessed with the AccuSway(PLUS ) platform ; Advanced Medical Technology Inc , Watertown , MA ) was the primary endpoint . Secondary endpoints included the short physical performance battery ( SPPB ) and serum 25(OH)D concentrations . An analysis of covariance model was used for treatment comparisons . Safety and tolerability were monitored . RESULTS Serum 25(OH)D concentrations rose significantly ( from 13.9 to 26.2 ng/mL , P < 0.001 ) in patients treated with 8400 IU vitamin D(3 ) but not in patients treated with the placebo . After 16 wk , neither mediolateral sway nor SPPB differed significantly between treatment groups . However , in the post hoc analysis of patients subgrouped by baseline sway ( > or = 0.46 compared with < 0.46 cm ) , treatment with 8400 IU vitamin D(3 ) significantly reduced sway compared with treatment with placebo ( P = 0.047 ) in patients with elevated baseline sway but not in patients with normal baseline sway . Adverse experiences and incidences of hypercalcemia , hypercalciuria , and elevated creatinine were similar with both treatments . In patients treated with 8400 IU vitamin D(3 ) , but not in placebo-treated patients , parathyroid hormone decreased significantly . CONCLUSIONS Weekly treatment with 8400 IU vitamin D(3 ) raised 25(OH)D concentrations in elderly , vitamin D-insufficient individuals . Treatment with 8400 IU vitamin D(3 ) did not reduce mediolateral sway significantly compared with treatment with placebo in this population , although in post hoc analysis , treatment with 8400 IU vitamin D(3 ) reduced sway in the subgroup of patients who had elevated sway at baseline . Weekly treatment with 8400 IU vitamin D(3 ) was well tolerated . This trial was registered at clinical trials.gov as NCT00242476
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 .