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 .
Baseline Characteristics of the Vitamin D and Type 2 Diabetes (D2d) Study: A Contemporary Prediabetes Cohort That Will Inform Diabetes Prevention Efforts
OBJECTIVE To describe baseline characteristics of the Vitamin D and Type 2 Diabetes ( D2d ) study , the first large U.S. diabetes prevention clinical trial to apply current American Diabetes Association ( ADA ) criteria for prediabetes . RESEARCH DESIGN AND METHODS This is a multicenter ( n = 22 sites ) , r and omized , double-blind , placebo-controlled , primary prevention clinical trial testing effects of oral daily 4,000 IU cholecalciferol ( D3 ) compared with placebo on incident diabetes in U.S. adults at risk for diabetes . Eligible participants were at risk for diabetes , defined as not meeting criteria for diabetes but meeting at least two 2010 ADA glycemic criteria for prediabetes : fasting plasma glucose ( FPG ) 100–125 mg/dL , 2-h postload glucose ( 2hPG ) after a 75-g oral glucose load 140–199 mg/dL , and /or a hemoglobin A1c ( HbA1c ) 5.7–6.4 % ( 39–46 mmol/mol ) . RESULTS A total of 2,423 participants ( 45 % of whom were women and 33 % nonwhite ) were r and omized to cholecalciferol or placebo . Mean ( SD ) age was 60 ( 9.9 ) years and BMI 32.1 ( 4.5 ) kg/m2 . Thirty-five percent met all three prediabetes criteria , 49 % met the FPG/HbA1c criteria only , 9.5 % met the 2hPG/FPG criteria only , and 6.3 % met the 2hPG/HbA1c criteria only . Black participants had the highest mean HbA1c and lowest FPG concentration compared with white , Asian , and other races ( P < 0.01 ) ; 2hPG concentration did not differ among racial groups . When compared with previous prediabetes cohorts , the D2d cohort had lower mean 2hPG concentration but similar HbA1c and FPG concentrations . CONCLUSIONS D2d will establish whether vitamin D supplementation lowers risk of diabetes and will inform about the natural history of prediabetes per contemporary ADA criteria
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 .