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 .
Estimation of the dietary requirement for vitamin D in free-living adults >=64 y of age.
BACKGROUND Older adults may be more prone to developing vitamin D deficiency than younger adults . Dietary requirements for vitamin D in older adults are based on limited evidence . OBJECTIVE The objective was to establish the dietary intake of vitamin D required to maintain serum 25-hydroxyvitamin D [ 25(OH)D ] concentrations above various cutoffs between 25 and 80 nmol/L during wintertime , which accounted for the effect of summer sunshine exposure and diet . DESIGN A r and omized , placebo-controlled , double-blind , 22-wk intervention was conducted in men and women aged > /=64 y ( n = 225 ) at supplemental levels of 0 , 5 , 10 , and 15 microg vitamin D(3)/d from October 2007 to March 2008 . RESULTS Clear dose-related increments ( P < 0.0001 ) in serum 25(OH)D were observed with increasing supplemental vitamin D(3 ) intakes . The slope of the relation between total vitamin D intake and serum 25(OH)D was 1.97 nmol . L(-1 ) . microg intake(-1 ) . The vitamin D intake that maintained serum 25(OH)D concentrations > 25 nmol/L in 97.5 % of the sample was 8.6 microg/d . Intakes were 7.9 and 11.4 microg/d in those who reported a minimum of 15 min daily summer sunshine exposure or less , respectively . The intakes required to maintain serum 25(OH)D concentrations of > 37.5 , > 50 , and > 80 nmol/L in 97.5 % of the sample were 17.2 , 24.7 , and 38.7 microg/d , respectively . CONCLUSION To ensure that the vitamin D requirement is met by the vast majority ( > 97.5 % ) of adults aged > /=64 y during winter , between 7.9 and 42.8 microg vitamin D/d is required , depending on summer sun exposure and the threshold of adequacy of 25(OH)D. This trial was registered at http://www.controlled-trials.com/IS RCT N20236112 as IS RCT N registration no. IS RCT N20236112
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 .