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 milk and calcium supplementation on bone density and bone turnover in pregnant Chinese women: a randomized controlled trail
Objective Calcium dem and is increased during pregnancy . However , few r and omized controlled trials examined the effects of calcium supplementation on bone mass during pregnancy . This study determined effects of calcium and milk supplementation on maternal bone mineral density ( BMD ) and bone turnover in pregnant Chinese women with habitual low calcium intake . Methods In this r and omized controlled trial , 36 Chinese pregnant women ( 24–31 years , 18 gestational weeks ) were r and omly assigned to the following three arms ( 12 each ) : I , usual diet ; II , “ I ” + 45 g milk powder ( containing 350 mg calcium ) ; or III , “ II ” + 600 mg calcium/day from gestational age of 20 weeks to 6 weeks post-partum ( PP ) . BMD was measured post-treatment using dual-energy X-ray absorptiometry . Dietary intakes , 24-h urinary calcium , bone resorption ( urinary hydroxyproline ) and formation ( serum osteocalcin ) biomarkers were examined at the gestational age of 20 and 34 weeks , and 6 weeks PP . Results A dose-dependent relationship was observed between calcium intake and BMDs . The BMD values were significantly higher in subjects with calcium and milk supplementation  than those in the controls at the whole body and spine ( p < 0.05 ) but not at the hip sites . We found significant decreases in changes of urinary hydroxyproline , and significant increases in serum osteocalcin during the intervention period in the calcium/milk intervention groups than those in the control group ( all p < 0.05 ) . Conclusion Calcium/milk supplementation during pregnancy is associated with greater BMD at the spine and whole body and suppresses bone resorption in Chinese women with habitual low calcium intake
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 .