Calcium supplements  increased BMD by 0.7 - 1.8 % at all five skeletal sites at one , two , and over two and a half years , but the size of the increase in BMD at later time points was similar to the increase at one year .
Increasing calcium intake from dietary sources or by taking calcium supplements produces small non-progressive increases in BMD , which are unlikely to lead to a clinical ly significant reduction in risk of fracture
OBJECTIVE To determine whether increasing calcium intake from dietary sources affects  bone mineral density ( BMD ) and , if so , whether the effects are similar to those of calcium supplements .
Effect of alendronate on risk of fracture in women with low bone density but without vertebral fractures: results from the Fracture Intervention Trial.
CONTEXT Alendronate sodium reduces fracture risk in postmenopausal women who have vertebral fractures , but its effects on fracture risk have not been studied for women without vertebral fractures . OBJECTIVE To test the hypothesis that 4 years of alendronate would decrease the risk of clinical and vertebral fractures in women who have low bone mineral density ( BMD ) but no vertebral fractures . DESIGN R and omized , blinded , placebo-controlled trial . SETTING Eleven community-based clinical research centers . SUBJECTS Women aged 54 to 81 years with a femoral neck BMD of 0.68 g/cm2 or less ( Hologic Inc , Waltham , Mass ) but no vertebral fracture ; 4432 were r and omized to alendronate or placebo and 4272 ( 96 % ) completed outcome measurements at the final visit ( an average of 4.2 years later ) . INTERVENTION All participants reporting calcium intakes of 1000 mg/d or less received a supplement containing 500 mg of calcium and 250 IU of cholecalciferol . Subjects were r and omly assigned to either placebo or 5 mg/d of alendronate sodium for 2 years followed by 10 mg/d for the remainder of the trial . MAIN OUTCOME MEASURES Clinical fractures confirmed by x-ray reports , new vertebral deformities detected by morphometric measurements on radiographs , and BMD measured by dual x-ray absorptiometry . RESULTS Alendronate increased BMD at all sites studied ( P<.001 ) and reduced clinical fractures from 312 in the placebo group to 272 in the intervention group , but not significantly so ( 14 % reduction ; relative hazard [ RH ] , 0.86 ; 95 % confidence interval [ CI ] , 0.73 - 1.01 ) . Alendronate reduced clinical fractures by 36 % in women with baseline osteoporosis at the femoral neck ( > 2.5 SDs below the normal young adult mean ; RH , 0.64 ; 95 % CI , 0.50 - 0.82 ; treatment-control difference , 6.5 % ; number needed to treat [ NNT ] , 15 ) , but there was no significant reduction among those with higher BMD ( RH , 1.08 ; 95 % CI , 0.87 - 1.35 ) . Alendronate decreased the risk of radiographic vertebral fractures by 44 % overall ( relative risk , 0.56 ; 95 % CI , 0.39 - 0.80 ; treatment-control difference , 1.7 % ; NNT , 60 ) . Alendronate did not increase the risk of gastrointestinal or other adverse effects . CONCLUSIONS In women with low BMD but without vertebral fractures , 4 years of alendronate safely increased BMD and decreased the risk of first vertebral deformity .  Alendronate significantly reduced the risk of clinical fractures among women with osteoporosis but not among women with higher BMD
Calcium supplements  increased BMD by 0.7 - 1.8 % at all five skeletal sites at one , two , and over two and a half years , but the size of the increase in BMD at later time points was similar to the increase at one year .
Increasing calcium intake from dietary sources or by taking calcium supplements produces small non-progressive increases in BMD , which are unlikely to lead to a clinical ly significant reduction in risk of fracture
OBJECTIVE To determine whether increasing calcium intake from dietary sources affects  bone mineral density ( BMD ) and , if so , whether the effects are similar to those of calcium supplements .