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 .
HRT and Vit D in prevention of non-vertebral fractures in postmenopausal women; a 5 year randomized trial.
OBJECTIVES We investigated the incidence of new non-vertebral fractures  during HRT or low-dose vitamin ( Vit ) D3 supplementation in a 5-year prospect i ve trial . METHODS A total of 464 early postmenopausal women , ( a subgroup of the Kuopio Osteoporosis Study , n = 13,100 ) were r and omized to four groups : ( 1 ) HRT , a sequential combination of 2 mg estradiol valerate and 1 mg cyproterone acetate ; ( 2 ) Vit D ( 300 IU/day and 100 IU/day during the fifth years ) ; ( 3 ) HRT + Vit D ; and ( 4 ) placebo .  Lumbar ( L2 - 4 ) and femoral neck bone mineral densities ( BMD ) were determined by dual X-ray absorptiometry ( DXA ) at baseline , after 2.5 and 5 years of treatment . All new symptomatic non-vertebral , radiographically defined fractures were recorded . RESULTS Altogether , 368 women ( 79 % ) completed the 5 year treatment . In all , 32 women had 39 non-vertebral fractures during a mean of 4.3 year follow-up ( HRT 4 , Vit D 10 , HRT + Vit D 8 and placebo 17 ) . The reduction in the incidence of new non-vertebral fractures was significant in women with HRT alone ( P = 0.032 ) when adjusted by baseline BMD and previous fractures ; observed also with the intention-to-treat principle ( P = 0.048 ) . When the HRT groups were pooled , HRT showed a significantly lower incidence of new non-vertebral fractures ( P = 0.042 ) than women receiving placebo and also after adjusting as above ( P = 0.016 ) ; both in valid-case and in the intention-to-treat analysis . In the Vit D group , the fracture incidence was non-significantly decreased ( P = 0.229 ) in comparison with the placebo group . The estimated risk of new non-vertebral fractures among women treated with HRT alone was 0.29 ( 95 % CI , 0.10 - 0.90 ) and with Vit D 0.47 ( 95 % CI , 0.20 - 1.14 ) and with HRT + Vit D 0.44 ( 95 % CI , 0.17 - 1.15 ) , in comparison with the placebo group ( adjusted by femoral BMD and previous fractures ) . CONCLUSIONS This study is the first prospect i ve trial confirming the beneficial effect of HRT on prevention of peripheral fractures in non-osteoporotic postmenopausal women . The effect of low-dose Vit D remains to be proved
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 .