Conclusions and Relevance In this systematic review and meta- analysis , neither intermittent nor daily dosing with st and ard doses of vitamin D alone was associated with reduced risk of fracture , but daily supplementation with both vitamin D and calcium was a more promising strategy
Importance Vitamin D and calcium supplements are recommended for the prevention of fracture , but previous r and omized clinical trials ( RCTs ) have reported conflicting results , with uncertainty about optimal doses and regimens for supplementation and their overall effectiveness .
Objective To assess the risks of fracture associated with differences in concentrations of 25-hydroxyvitamin D ( 25[OH]D ) in observational studies and the risks of fracture associated with supplementation with vitamin D alone or in combination with calcium in RCTs .
Can vitamin D supplementation reduce the risk of fracture in the elderly? A randomized controlled trial.
R and omized controlled trials have shown that a combination of vitamin D and calcium can prevent  fragility fractures in the elderly . Whether this effect is attributed to the combination of vitamin D and calcium or to one of these nutrients alone is not known . We studied if an intervention with 10 microg of vitamin D3 per day could prevent hip fracture and other osteoporotic fractures in a double-blinded r and omized controlled trial . Residents from 51 nursing homes were allocated r and omly to receive 5 ml of ordinary cod liver oil ( n = 569 ) or 5 ml of cod liver oil where vitamin D was removed ( n = 575 ) . During the study period of 2 years , fractures and deaths were registered , and the principal analysis was performed on the intention-to-treat basis . Biochemical markers were measured at baseline and after 1 year in a sub sample . Forty-seven persons in the control group and 50 persons in the vitamin D group suffered a  hip fracture . The corresponding figures for all nonvertebral fractures were 76 persons ( control group ) and 69 persons ( vitamin D group ) . There was no difference in the incidence of hip fracture ( p = 0.66 , log-rank test ) , or in the incidence of all nonvertebral fractures ( p = 0.60 , log-rank test ) in the vitamin D group compared with the control group . Compared with the control group , persons in the vitamin D group increased their serum 25-hydroxyvitamin D concentration with 22 nmol/liter ( p = 0.001 ) . In conclusion , we found that an intervention with 10 microg of vitamin D3 alone produced no fracture-preventing effect in a nursing home population of frail elderly people
Conclusions and Relevance In this systematic review and meta- analysis , neither intermittent nor daily dosing with st and ard doses of vitamin D alone was associated with reduced risk of fracture , but daily supplementation with both vitamin D and calcium was a more promising strategy
Importance Vitamin D and calcium supplements are recommended for the prevention of fracture , but previous r and omized clinical trials ( RCTs ) have reported conflicting results , with uncertainty about optimal doses and regimens for supplementation and their overall effectiveness .
Objective To assess the risks of fracture associated with differences in concentrations of 25-hydroxyvitamin D ( 25[OH]D ) in observational studies and the risks of fracture associated with supplementation with vitamin D alone or in combination with calcium in RCTs .