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 .
Hip Fractures and Bone Mineral Density in the Elderly—Importance of Serum 25-Hydroxyvitamin D
Background The significance of serum 25-hydroxyvitamin D [ 25(OH)D ] concentrations for hip fracture risk of the elderly is still uncertain . Difficulties reaching both frail and healthy elderly people in r and omized controlled trials or large cohort studies may in part explain discordant findings . We determined hazard ratios for  hip fractures of elderly men and women related to serum 25(OH)D , including both the frail and the healthy segment of the elderly population . Methods The AGES-Reykjavik Study is a prospect i ve study of 5764 men and women , age 66–96 years , based on a representative sample of the population of Reykjavik , Icel and . Participation was 71.8 % .  Hazard ratios of incident hip fractures and baseline bone mineral density were determined according to serum concentrations of 25(OH)D at baseline . Results Mean follow-up was 5.4 years . Compared with referent values ( 50–75 nmol/L ) , hazard ratios for hip fractures were 2.24 ( 95 % CI 1.63 , 3.09 ) for serum 25(OH)D < 30 nmol/L , adjusting for age , sex , body mass index , height , smoking , alcohol intake and season , and 2.08 ( 95 % CI 1.51 , 2.87 ) , adjusting additionally for physical activity . No difference in risk was associated with 30–50 nmol/L or ≥75 nmol/L in either model compared with referent . Analyzing the sexes separately , hazard ratios were 2.61 ( 95 % CI 1.47 , 4.64 ) in men and 1.93 ( 95 % CI 1.31 , 2.84 ) in women . Values < 30 nmol/L were associated with significantly lower bone mineral density of femoral neck compared with referent , z-scores -0.14 ( 95 % CI −0.27 , −0.00 ) in men and −0.11 ( 95 % CI −0.22 , −0.01 ) in women . Conclusions Our results lend support to the overarching importance of maintaining serum 25(OH)D above 30 nmol/L for bone health of elderly people while potential benefits of having much higher levels could not be detected
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 .