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 .
Medium doses of daily vitamin D decrease falls and higher doses of daily vitamin D3 increase falls: A randomized clinical trial
Falls are a serious health problem in the aging population . Because low levels of vitamin D have been associated with increased fall rates , many trials have been performed with vitamin D ; two meta-analyses showed either a small effect or no effect of vitamin D on falls . We conducted a study of the effect of vitamin D on serum 25 hydroxyvitamin D ( 25OHD ) and data on falls was collected as a secondary outcome . In a 12-month double blind r and omized placebo trial , elderly women , mean age 66 years , were r and omized to one of seven daily oral doses of vitamin D or placebo . The main inclusion criterion for study was a baseline serum 25OHD<20ng/ml ( 50nmol/L ) . A history of falls was collected at baseline and fall events were collected every 3 months . Results showed that the effect of vitamin D on falls followed a U-shaped curve whether analyzed by dose or serum 25OHD levels . There was no decrease in falls on low vitamin D doses 400 , 800 IU , a significant decrease on medium doses 1600 , 2400,3200 IU ( p=0.020 ) and no decrease on high doses 4000 , 4800 IU compared to placebo ( p=0.55 ) . When compared to 12-month serum 25OHD quintiles , the faller rate was 60 % in the lowest quintile < 25ng/ml ( < 50nmol/L ) , 21 % in the low middle quintile 32 - 38ng/ml ( 80 - 95nmo/L ) , 72 % in the high middle quintile 38 - 46ng/ml ( 95 - 115nmo/L ) and 45 % in the highest quintile 46 - 66ng/ml ( 115 - 165nmol/L ) . In the subgroup with a fall history , fall rates were 68 % on low dose , 27 % on medium doses and 100 % on higher doses . Fall rates on high doses were increased compared to medium doses ( Odds Ratio 5.6.95 % CI : 2.1 - 14.8 ) . In summary , the maximum decrease in falls corresponds to a 12- month serum 25OHD of 32 - 38ng/ml ( 80 - 95nmol/L ) and faller rates increase as serum 25OHD exceed 40 - 45ng/ml ( 100 - 112.5nmol/L ) . The Tolerable upper limit ( TUL ) recently increased in 2010 from 2000 to 4000 IU/day may need to be reduced in elderly women especially in those with a fall history
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 .