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 .
Effect of vitamin D, calcium and multiple micronutrient supplementation on vitamin D and bone status in Bangladeshi premenopausal garment factory workers with hypovitaminosis D: a double-blinded, randomised, placebo-controlled 1-year intervention.
Due to little outdoor activity and low dietary intake of vitamin D ( VD ) , Bangladeshi low-income women are at risk for osteoporosis at an early age . The present study assessed the effect of VD , Ca and multiple micronutrient supplementation on VD and bone status in Bangladeshi young female garment factory workers . This placebo-controlled 1-year intervention r and omly assigned 200 apparently healthy subjects ( aged 16 - 36 years ) to four groups : VD group , daily 10 microg VD ; VD and Ca ( VD-Ca ) group , daily 10 microg VD+600 mg Ca ; multiple micronutrient and Ca ( MMN-Ca ) group , 10 microg VD and other micronutrients+600 mg Ca ; a placebo group .  Serum 25-hydroxyvitamin D ( S-25OHD ) , intact parathyroid hormone ( S-iPTH ) , Ca , phosphate and alkaline phosphatase were measured . Bone mineral density and bone mineral content were measured by dual-energy X-ray absorptiometry . All measurements were made at baseline and at 12 months . Significantly ( P < 0.001 ) higher S-25OHD concentrations were observed in the supplemented groups than in the placebo group after the intervention . Supplementation had an effect ( P < 0.001 ) on S-iPTH in the VD-Ca and MMN-Ca groups compared with the placebo group . Bone mineral augmentation increased at the femur in the supplemented groups . Supplementation with VD-Ca should be recommended as a strategic option to reduce the risk of osteomalacia and osteoporosis in these subjects . MMN-Ca may have analogous positive health implication s with additional non-skeletal benefits
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 .