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 .
Comparative effects of oral aromatic and branched-chain amino acids on urine calcium excretion in humans
Summary In 30 adults , increasing intake of aromatic amino acids increased calcium excretion and serum IGF-1 , but not indices of bone turnover , when compared with similar increases in intake of branched-chain amino acids . The mechanisms involved are not certain but these findings suggest a role for the calcium sensor receptor . Introduction In contrast to branched-chain amino acids ( BCAAs ) , aromatic amino acids ( AAAs ) bind to the calcium sensing receptor ( CaR ) and thus have an increased potential to affect calcium homeostasis . In this study we compare the effects of increased intake of AAAs versus BCAAs on calcium excretion , serum IGF-1 , markers of bone turnover , and 4-hr calcium excretion after an oral calcium load . Methods After two weeks on low-protein metabolic diets , 30 healthy subjects were r and omized to a fivefold increase in intake of AAAs or BCAAs for two weeks . Changes in calcium excretion and other measures were compared in the two groups . Results With the increase in amino acid intake , 24-hr calcium excretion ( P = 0.027 ) , IGF-1 ( P = 0.022 ) , and 4-hr calcium excretion after an oral load ( P = 0.023 ) increased significantly in the AAA relative to the BCAA group . Group changes in turnover markers did not differ significantly . Conclusion In comparison with BCAAs , AAAs promoted calcium excretion . The calciuria does not appear to result from increases in bone resorption and may occur by increasing calcium absorption . The AAAs also increased circulating levels of IGF-1 . Collectively these findings raise the possibility that AAAs may selectively influence calcium homeostasis through their interactions with the
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 .