For hip fracture , at a 15 % relative risk , the effect estimate lay between the futility boundary and the inferior boundary , meaning there is reliable evidence that vitamin D supplementation does not reduce hip fractures by this amount , but uncertainty remains as to whether it might increase hip fractures .
The effect estimate lay within the futility boundary at thresholds of 0·5 % for total hip , forearm , and total body bone mineral density , and 1·0 % for lumbar spine and femoral neck , providing reliable evidence that vitamin D does not alter these outcomes by these amounts .
INTERPRETATION Our findings suggest that vitamin D supplementation does not prevent fractures or falls , or have clinical ly meaningful effects on bone mineral density .
There were no differences between the effects of higher and lower doses of vitamin D. There is little justification to use vitamin D supplements to maintain or improve musculoskeletal health .
BACKGROUND The effects of vitamin D on fractures , falls , and bone mineral density are uncertain , particularly for high vitamin D doses .
We aim ed to determine the effect of vitamin D supplementation on fractures , falls , and bone density .
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
For hip fracture , at a 15 % relative risk , the effect estimate lay between the futility boundary and the inferior boundary , meaning there is reliable evidence that vitamin D supplementation does not reduce hip fractures by this amount , but uncertainty remains as to whether it might increase hip fractures .
The effect estimate lay within the futility boundary at thresholds of 0·5 % for total hip , forearm , and total body bone mineral density , and 1·0 % for lumbar spine and femoral neck , providing reliable evidence that vitamin D does not alter these outcomes by these amounts .
INTERPRETATION Our findings suggest that vitamin D supplementation does not prevent fractures or falls , or have clinical ly meaningful effects on bone mineral density .
There were no differences between the effects of higher and lower doses of vitamin D. There is little justification to use vitamin D supplements to maintain or improve musculoskeletal health .
BACKGROUND The effects of vitamin D on fractures , falls , and bone mineral density are uncertain , particularly for high vitamin D doses .
We aim ed to determine the effect of vitamin D supplementation on fractures , falls , and bone density .