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 .
Potassium bicarbonate attenuates the urinary nitrogen excretion that accompanies an increase in dietary protein and may promote calcium absorption.
CONTEXT Protein is an essential component of muscle and bone . However , the acidic byproducts of protein metabolism may have a negative impact on the musculoskeletal system , particularly in older individuals with declining renal function . OBJECTIVE We sought to determine whether adding an alkaline salt , potassium bicarbonate ( KHCO3 ) , allows protein to have a more favorable net impact on intermediary indices of muscle and bone conservation than it does in the usual acidic environment . DESIGN We conducted a 41-d r and omized , placebo-controlled , double-blind study of KHCO3 or placebo with a 16-d phase-in and two successive 10-d metabolic diets containing low ( 0.5 g/kg ) or high ( 1.5 g/kg ) protein in r and om order with a 5-d washout between diets . SETTING The study was conducted in a metabolic research unit . PARTICIPANTS Nineteen healthy subjects ages 54 - 82 yr participated . INTERVENTION KHCO3 ( up to 90 mmol/d ) or placebo was administered for 41 d. MAIN OUTCOME MEASURES We measured 24-h urinary nitrogen excretion , IGF-I , 24-h urinary calcium excretion , and fractional calcium absorption . RESULTS KHCO3 reduced the rise in urinary nitrogen excretion that accompanied an increase in protein intake ( P = 0.015 ) and was associated with higher IGF-I levels on the low-protein diet ( P = 0.027 ) with a similar trend on the high-protein diet ( P = 0.050 ) . KHCO3 was also associated with higher fractional calcium absorption on the low-protein diet ( P = 0.041 ) with a similar trend on the high-protein diet ( P = 0.064 ) . CONCLUSIONS In older adults , KHCO3 attenuates the protein-induced rise in urinary nitrogen excretion , and this may be mediated by IGF-I. KHCO3 may also promote calcium absorption independent of the dietary protein content
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 .