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 .
The Effect of a Whey Protein Supplement on Bone Mass in Older Caucasian Adults.
CONTEXT It has been assumed that the increase in urine calcium ( Ca ) that accompanies an increase in dietary protein was due to increased bone resorption . However , studies using stable Ca isotopes have found that dietary protein increases Ca absorption without increasing bone resorption . OBJECTIVE The objective of the study was to investigate the impact of a moderately high protein diet on bone mineral density ( BMD ) . DESIGN This was a r and omized , double-blind , placebo-controlled trial of protein supplementation daily for 18 months . SETTING The study was conducted at two institutional research centers . PARTICIPANTS Two hundred eight older women and men with a body mass index between 19 and 32 kg/m(2 ) and a self-reported protein intake between 0.6 and 1.0 g/kg participated in the study . INTERVENTION Subjects were asked to incorporate either a 45-g whey protein or isocaloric maltodextrin supplement into their usual diet for 18 months . MAIN OUTCOME MEASURE BMD by dual-energy x-ray absorptiometry , body composition , and markers of skeletal and mineral metabolism were measured at baseline and at 9 and 18 months . RESULTS There were no significant differences between groups for changes in L-spine BMD ( primary outcome ) or the other skeletal sites of interest . Truncal lean mass was significantly higher in the protein group at 18 months ( P = .048 ) . C-terminal telopeptide ( P = .0414 ) , IGF-1 ( P = .0054 ) , and urinary urea ( P < .001 ) were also higher in the protein group at the end of the study period . There was no difference in estimated glomerular filtration rate at 18 months . CONCLUSION Our data suggest that protein supplementation above the recommended dietary allowance ( 0.8 g/kg ) may preserve fat-free mass without adversely affecting skeletal health or renal function in healthy older adults
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 .