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 .
Calciotropic hormones and the risk of hip and nonspine fractures in older adults: the Health ABC Study.
The effects of vitamin D and parathyroid hormone ( PTH ) levels on incident fracture remain uncertain . To test the hypothesis that increasing serum 25-hydroxyvitamin D [ 25(OH)D ] and decreasing PTH levels are associated with decreased risk of hip and any nonspine fracture , we conducted a prospect i ve cohort study among 2614 community-dwelling white and black participants , aged ≥70 years , from the Health , Aging and Body Composition ( Health ABC ) Study . Serum and plasma sample s were drawn at year 2 , which formed the baseline for this analysis . Serum 25(OH)D and intact PTH ( 1 - 84 ) were measured using radioimmunoassay with DiaSorin reagents and EDTA plasma with a two-site immunoradiometric assay kit , respectively . Incident fractures ( hip and any nonspine ) were assessed after year 2 , every 6 months , by self-report and vali date d by radiology reports . The median ( interquartile range ) follow-up times for hip and any nonspine fractures were 6.4 ( 6.1 - 6.5 ) and 6.4 ( 5.5 - 6.5 ) years , respectively . Cox proportional hazards regression was used to estimate the hazard ratios ( HR ) with 95 % confidence intervals ( CI ) for fracture . There were 84 hip and 247 nonspine fractures that occurred over the follow-up period . The multivariable adjusted HRs ( 95 % CIs ) of hip fracture for participants in the lowest ( ≤17.78 ng/mL ) , second ( 17.79 to 24.36 ng/mL ) , and third quartiles ( 24.37 to 31.94 ng/mL ) of 25(OH)D were 1.92 ( 0.97 to 3.83 ) , 0.75 ( 0.32 to 1.72 ) and 1.86 ( 1.00 to 3.45 ) , respectively , compared with participants in the highest 25(OH)D quartile ( > 31.94 ng/mL ) ( p trend = 0.217 ) . Additional adjustment for IL-6 ( p = 0.107 ) , PTH ( p = 0.124 ) , and hip areal bone mineral density ( p = 0.137 ) attenuated HRs of hip fracture in the lowest quartile by 16.3 % , 17.4 % , and 26.1 % , respectively . There was no evidence of an association between 25(OH)D and any nonspine fractures , or between PTH and hip or any nonspine fractures . We found limited evidence to support an association between calciotropic hormones and hip and nonspine fractures in older men and women
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 .