In older people with osteoporosis , higher protein intake ( ≥ 0.8-g/kg body weight/day , i.e. , above the current RDA ) is associated with higher BMD , a slower rate of bone loss , and reduced risk of hip fracture , provided that dietary calcium intakes are adequate .
Intervention with dietary protein supplements attenuate age-related BMD decrease and reduce bone turnover marker levels , together with an increase in IGF-I and a decrease in PTH .
There is no evidence that diet-derived acid load is deleterious for bone health .
Thus , insufficient dietary protein intakes may be a more severe problem than protein excess in the elderly .
A summary of systematic review s and meta-analyses addressing the benefits and risks of dietary protein intakes  for  bone health in adults suggests that dietary protein levels even above the current RDA may be beneficial in reducing bone loss and hip fracture risk , provided calcium intakes are adequate .
Several systematic review s and meta-analyses have addressed the benefits and risks of dietary protein intakes for bone health in adults .
Adequate supplies of dietary protein are required for optimal bone growth and maintenance of healthy bone .
Variation in protein intakes within the “ normal ” range accounts for 2–4 % of BMD variance in adults .
Long-term effects of calcium-vitamin-D3-fortified milk on bone geometry and strength in older men.
The long-term effects of calcium and vitamin D supplementation on bone material and structural properties in older men are not known . The aim of this study was to examine the effects of high calcium ( 1000 mg/day)- and vitamin-D(3 ) ( 800 IU/day)-fortified milk on cortical and trabecular volumetric BMD ( vBMD ) and bone geometry at the axial and appendicular skeleton in men aged over 50 years . One hundred and eleven men who were part of a larger 2-year r and omized controlled trial had QCT scans  of the mid-femur and lumbar spine ( L(1)-L(3 ) ) to assess vBMD , bone geometry and indices of bone strength [ polar moment of inertia ( I(polar ) ) ] . After 2 years , there were no significant differences between the milk supplementation and control group for the change in any mid-femur or L(1)-L(3 ) bone parameters for all men aged over 50 years . However , the mid-femur skeletal responses to the fortified milk varied according to age , with a split of < or=62 versus > 62 years being the most significant for discriminating the changes between the two groups . Subsequent analysis revealed that , in the older men ( > 62 years ) , the expansion in mid-femur medullary area was 2.8 % ( P < 0.01 ) less in the milk supplementation compared to control group , which helped to preserve cortical area in the milk supplementation group ( between group difference 1.1 % , P < 0.01 ) . Similarly , for mid-femur cortical vBMD and I(polar ) , the net loss was 2.3 and 2.8 % less in the milk supplementation compared to control group ( P < 0.01 and < 0.001 , respectively ) . In conclusion , calcium-vitamin-D(3)-fortified milk may represent an effective strategy to maintain bone strength by preventing endocortical bone loss and slowing the loss in cortical vBMD in elderly men
In older people with osteoporosis , higher protein intake ( ≥ 0.8-g/kg body weight/day , i.e. , above the current RDA ) is associated with higher BMD , a slower rate of bone loss , and reduced risk of hip fracture , provided that dietary calcium intakes are adequate .
Intervention with dietary protein supplements attenuate age-related BMD decrease and reduce bone turnover marker levels , together with an increase in IGF-I and a decrease in PTH .
There is no evidence that diet-derived acid load is deleterious for bone health .
Thus , insufficient dietary protein intakes may be a more severe problem than protein excess in the elderly .
A summary of systematic review s and meta-analyses addressing the benefits and risks of dietary protein intakes  for  bone health in adults suggests that dietary protein levels even above the current RDA may be beneficial in reducing bone loss and hip fracture risk , provided calcium intakes are adequate .
Several systematic review s and meta-analyses have addressed the benefits and risks of dietary protein intakes for bone health in adults .
Adequate supplies of dietary protein are required for optimal bone growth and maintenance of healthy bone .
Variation in protein intakes within the “ normal ” range accounts for 2–4 % of BMD variance in adults .