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 .
Effect of calcium fortified milk supplementation with or without vitamin K on biochemical markers of bone turnover in premenopausal women.
OBJECTIVE We compared the effect of supplementation with a fortified skimmed milk product ( high calcium skim milk ) with or without added phylloquinone ( vitamin K(1 ) ) on markers of bone formation and resorption in premenopausal women . METHODS Eighty-two women 20 to 35 y of age were r and omly allocated to three groups . Two groups received two daily servings of high calcium skim milk ( 1000 mg/d of extra calcium ) with or without added phylloquinone ( 80 microg/d ) for 16 wk , and a third control group received no supplementation .  Bone density was assessed at baseline and the bone markers , total osteocalcin , type I N-terminal procollagen peptide , and cross-linked C-telopeptide of type I collagen were measured at baseline and at weeks 2 , 12 , and 16 . Serum phylloquinone and undercarboxylated osteocalcin were measured in the control and vitamin K-supplemented groups at weeks 0 and 16 . RESULTS Baseline values for age , body mass index , and bone density did not differ across groups . In vitamin K-supplemented women , mean serum phylloquinone concentrations increased from 0.27 to 0.76 microg/L ( P < 0.05 ) and undercarboxylated osteocalcin concentrations decreased from 9.68 to 4.46 microg/L ( P < 0.05 ) over 16 wk . Plasma cross-linked C-telopeptide of type I collagen , total osteocalcin , and type I N-terminal procollagen peptide levels decreased significantly in both supplemented groups compared with the control group over 16 wk ( cross-linked C-telopeptide of type I collagen > 30 % , total osteocalcin and type I N-terminal procollagen peptide > 15 % ) . CONCLUSION Fortified milk supplementation  in premenopausal women reduced bone turnover significantly . Phylloquinone fortification substantially improved vitamin K status but had no demonstrable additive effect on bone turnover in this short-term study
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 .