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 .
Effects of Vitamin D3 Supplementation on Lean Mass, Muscle Strength, and Bone Mineral Density During Weight Loss: A Double-Blind Randomized Controlled Trial.
OBJECTIVES To compare the effects of 12 months of vitamin D3 supplementation with that placebo on lean mass , bone mineral density ( BMD ) , and muscle strength in overweight or obese postmenopausal women completing a structured weight-loss program . DESIGN Double-blind , placebo-controlled r and omized clinical trial . SETTING Fred Hutchinson Cancer Research Center , Seattle , Washington . PARTICIPANTS Postmenopausal women aged 50 to 75 with a body mass index ( BMI ) of 25 kg/m(2 ) or greater and a serum 25-hydroxyvitamin D ( 25(OH)D ) concentration between 10.0 and 32.0 ng/mL ( insufficient ) ( N = 218 ) . INTERVENTION Oral vitamin D3 2,000 IU/d or placebo in combination with a lifestyle-based weight loss intervention consisting of a reduction of 500 kcal to 1,000 kcal per day and 225 min/wk of moderate- to vigorous-intensity aerobic exercise .  MEASUREMENTS Serum 25(OH)D , body composition , and muscle strength were measured before r and omization ( baseline ) and at 12 months . Mean changes of the groups were compared ( intention to treat ) using generalized estimating equations . RESULTS Change in 25(OH)D was significantly different between the vitamin D and placebo groups at 12 months ( 13.6 ng/mL vs -1.3 ng/mL , P < .001 ) , but no differences in change in lean mass ( -0.8 kg vs -1.1 kg , P = .53 ) or BMD of the spine ( -0.01 g/cm(2 ) vs 0.0 g/cm(2 ) , P = .82 ) or right femoral neck ( both -0.01 g/cm(2 ) , P = .49 ) were detected between the groups . Leg strength decreased in the vitamin D group but not in the placebo group ( -2.6 pounds vs 1.8 pounds , P = .03 ) . In women r and omized to vitamin D , achieving repletion ( 25(OH)D ≥ 32 ng/mL ) did not alter results . CONCLUSION Vitamin D3 supplementation during weight-loss decreased leg strength but did not alter changes in lean mass or BMD in postmenopausal women with vitamin D insufficiency
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 .