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 .
The effect of high-dose vitamin D3 supplementation on bone mineral density in subjects with prediabetes
Summary The rationale of this study was to determine the effect of high-dose vitamin D3 supplementation on bone mineral density ( BMD ) .  Prediabetic males given vitamin D had significantly less reduction in BMD at the femoral neck compared to the controls . The clinical implication s of our findings require further investigation . Introduction Type 2 diabetes mellitus is associated with increased fracture risk , and recent studies show crosstalk between bone and glucose metabolism . Few studies have investigated the effect of vitamin D supplementation on the bone without additional calcium . In the present study , we aim ed to determine whether a high dose of vitamin D3 could improve bone mass density ( BMD ) in prediabetic subjects . Methods The current study was conducted as a secondary research on a previously performed trial , in which 511 subjects with prediabetes were r and omized to vitamin D3 ( 20,000 IU per week ) versus placebo for 5 years  . BMD was measured using dual-energy X-ray absorptiometry ( DEXA ) . Results Two hundred and fifty-six subjects were r and omized to vitamin D and 255 to placebo . Mean baseline serum 25-hydroxyvitamin D ( 25(OH)D ) level was 60 nmol/L. Two hundred and two and 214 in the vitamin D and placebo groups , respectively , completed BMD measurements , whereas one in each group was excluded due to use of bisphosphonates . Males given vitamin D had significantly less reduction in BMD at the femoral neck measurement site compared to the controls ( 0.000 versus − 0.010 g/cm2 , p = 0.008 ) . No significant differences between intervention groups were seen at the total hip measurement site , regarding both males and females . Conclusions Vitamin D3 supplementation alone may be beneficial in males with prediabetes , but confirmatory studies are needed
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 .