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 .
A high ratio of dietary animal to vegetable protein increases the rate of bone loss and the risk of fracture in postmenopausal women. Study of Osteoporotic Fractures Research Group.
BACKGROUND Different sources of dietary protein may have different effects on bone metabolism . Animal foods provide predominantly acid precursors , whereas protein in vegetable foods is accompanied by base precursors not found in animal foods . Imbalance between dietary acid and base precursors leads to a chronic net dietary acid load that may have adverse consequences on bone . OBJECTIVE We wanted to test the hypothesis that a high dietary ratio of animal to vegetable foods , quantified by protein content , increases bone loss and the risk of fracture . DESIGN This was a prospect i ve cohort study with a mean ( + /-SD ) of 7.0+/-1.5 y of follow-up of 1035 community-dwelling white women aged > 65 y.  Protein intake  was measured by using a food-frequency question naire and  bone mineral density was measured by dual-energy X-ray absorptiometry . RESULTS Bone mineral density was not significantly associated with the ratio of animal to vegetable protein intake . Women with a high ratio had a higher rate of bone loss at the femoral neck than did those with a low ratio ( P = 0.02 ) and a greater risk of hip fracture ( relative risk = 3.7 , P = 0.04 ) . These associations were unaffected by adjustment for age , weight , estrogen use , tobacco use , exercise , total calcium intake , and total protein intake . CONCLUSIONS Elderly women with a high dietary ratio of animal to vegetable protein intake  have more rapid femoral neck bone loss and a greater risk of hip fracture than do those with a low ratio . This suggests that an increase in vegetable protein intake and a decrease in animal protein intake may decrease bone loss and the risk of hip fracture . This possibility should be confirmed in other prospect i ve studies and tested in a r and omized trial
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 .