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 .
Vitamin D treatment in primary hyperparathyroidism: a randomized placebo controlled trial.
CONTEXT Low 25-hydroxyvitamin D levels are common in patients with primary hyperparathyroidism ( PHPT ) and associated with higher PTH levels and hungry bone syndrome after parathyroidectomy ( PTX ) . However , concerns have been raised about the safety of vitamin D supplementation in PHPT . OBJECTIVE We aim ed to assess safety and effects on calcium homeostasis and bone metabolism of supplementation with high doses of vitamin D in PHPT patients . DESIGN , SETTING This was an investigator-initiated double-blind , r and omized , placebo-controlled , parallel-group trial from a single center . PATIENTS Forty-six PHPT patients were recruited , with a mean age of 58 ( range 29 - 77 ) years , and 35 ( 76 % ) were women . INTERVENTIONS Intervention included daily supplementation with 70 μg ( 2800 IU ) cholecalciferol or identical placebo for 52 weeks . Treatment was administered 26 weeks before PTX and continued for 26 weeks after PTX . MAIN OUTCOME MEASURES PTH , calcium homeostasis , and bone metabolism were evaluated . RESULTS Preoperatively , 25-hydroxyvitamin D increased from 50 to 94 nmol/L in the treatment group and decreased from 57 to 52 nmol/L in the placebo group ( P < .001 ) . Compared with placebo , vitamin D  decreased PTH significantly by 17 % before PTX ( P = .01 ) , increased lumbar spine bone mineral density by 2.5 % ( P = .01 ) , and decreased C-terminal β-CrossLaps by 22 % ( P < .005 ) . The trabecular bone score did not change in response to treatment , but improved after PTX . Postoperatively , PTH remained lower in the cholecalciferol group compared with the placebo group ( P = .04 ) . Plasma creatinine and plasma and urinary calcium did not differ between groups . CONCLUSIONS Daily supplementation with a high vitamin D dose safely improves vitamin D status and decreases PTH in PHPT patients . The vitamin D treatment is accompanied by reduced bone resorption and improved bone mineral density before operation
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 .