Subgroup analyses showed that these results were generally consistent regardless of the calcium or vitamin D dose , sex , fracture history , dietary calcium intake , and baseline serum 25-hydroxyvitamin D concentration .
Conclusions and Relevance In this meta- analysis of r and omized clinical trials , the use of supplements that included calcium , vitamin D , or both compared with placebo or no treatment was not associated with a lower risk of fractures  among community-dwelling older adults .
Importance The increased social and economic burdens for osteoporosis-related fractures worldwide make the prevention of such injuries a major public health goal .
Previous studies have reached mixed conclusions regarding the association between calcium , vitamin D , or combined calcium and vitamin D supplements and fracture incidence in older adults .
Objective To investigate whether calcium , vitamin D , or combined calcium and vitamin D supplements are associated with a lower fracture incidence in community-dwelling older adults .
Design, history and results of the Thiazolidinedione Intervention with vitamin D Evaluation (TIDE) randomised controlled trial
Conflicting data regarding cardiovascular effects of thiazolidinediones ( TZDs ) and extra-skeletal effects of vitamin D supported the need for a definitive trial . The Thiazolidinedione Intervention with vitamin D Evaluation ( TIDE ) trial aim ed to assess the effects of TZDs ( rosiglitazone and pioglitazone ) on cardiovascular outcomes and the effects of vitamin D ( cholecalciferol ) on  cancers and mortality . A large multicentre 3 × 2 factorial double-blind placebo-controlled r and omised trial recruited from outpatient primary care and specialty clinics in 33 countries . From June 2009 to July 2010 , 1,332 people with type 2 diabetes and other cardiovascular risk factors aged ≥50 years whose HbA1c was 6.5–9.5 % ( 48–80 mmol/mol ) when using two or fewer glucose-lowering drugs were r and omised by a central computer system to placebo ( n = 541 ) , rosiglitazone 4–8 mg/day ( n = 399 ) or pioglitazone 30–45 mg/day ( n = 392 ) ; 1,221 participants were r and omised to placebo ( n = 614 ) or vitamin D 1,000 IU/day ( n = 607 ) . Participants and all study personnel were blind to treatment allocation . The primary outcome for the TZD arm was the composite of myocardial infa rct ion , stroke or cardiovascular death , and for the vitamin D arm it was cancer or all-cause death . All r and omised participants were included in the primary analysis . From the study design , 16,000 people were to be followed for approximately 5.5 years . However , the trial was stopped prematurely because of regulatory concerns after a mean of 162 days without consideration of the accrued data . In the TZD arm , the cardiovascular outcome occurred in five participants ( 0.9 % ) in the placebo groups and three participants ( 0.4 % ) in the TZD groups ( two allocated to pioglitazone , one to rosiglitazone ) . In the vitamin D arm , the primary outcome occurred in three participants ( 0.5 % ) in the placebo group and in two participants ( 0.3 % ) receiving vitamin D. Adverse events were comparable in all groups . Uncertainty persists regarding the clinical ly relevant risks and benefits of TZDs and vitamin D because of the early cancellation of this comprehensive trial . Clinical Trials.gov NCT00879970 The study was funded by GlaxoSmithKline
Subgroup analyses showed that these results were generally consistent regardless of the calcium or vitamin D dose , sex , fracture history , dietary calcium intake , and baseline serum 25-hydroxyvitamin D concentration .
Conclusions and Relevance In this meta- analysis of r and omized clinical trials , the use of supplements that included calcium , vitamin D , or both compared with placebo or no treatment was not associated with a lower risk of fractures  among community-dwelling older adults .
Importance The increased social and economic burdens for osteoporosis-related fractures worldwide make the prevention of such injuries a major public health goal .
Previous studies have reached mixed conclusions regarding the association between calcium , vitamin D , or combined calcium and vitamin D supplements and fracture incidence in older adults .
Objective To investigate whether calcium , vitamin D , or combined calcium and vitamin D supplements are associated with a lower fracture incidence in community-dwelling older adults .