Protein intake and lumbar bone density: the Multi-Ethnic Study of Atherosclerosis (MESA). Biomarker-calibrated protein intake and bone health in the Women's Health Initiative clinical trials and observational study. The Relation between Dietary Protein, Calcium and Bone Health in Women: Results from the EPIC-Potsdam Cohort Dietary protein intake and risk of osteoporotic hip fracture in elderly residents of Utah. Dietary protein and calcium interact to influence calcium retention: a controlled feeding study. Identification of a dietary pattern prospectively associated with bone mass in Australian young adults. Long-term protein intake and dietary potential renal acid load are associated with bone modeling and remodeling at the proximal radius in healthy children. Association of protein intake with bone mineral density and bone mineral content among elderly women: The OSTPRE fracture prevention study Dietary protein is associated with musculoskeletal health independently of dietary pattern: the Framingham Third Generation Study. Dietary phytochemical intake from foods and health outcomes: a systematic review protocol and preliminary scoping Whey Protein Supplementation and Higher Total Protein Intake Do Not Influence Bone Quantity in Overweight and Obese Adults Following a 36-Week Exercise and Diet Intervention. [Optimization of calcium intake for the prevention of osteoporosis and osteoporotic fractures: a review of the evidence]. Examining the theory‐effectiveness hypothesis: A systematic review of systematic reviews Bone Size and Bone Mass in 10-Year-Old Danish Children: Effect of Current Diet
 Calcium intake in health maintenance – a systematic review Effect of dietary protein supplements on calcium excretion in healthy older men and women. The Effect of a Whey Protein Supplement on Bone Mass in Older Caucasian Adults. Effect of protein supplementation during a 6-month strength and conditioning program on areal and volumetric bone parameters. Short-term changes in calcium but not protein intake alter the rate of bone resorption in healthy subjects as assessed by urinary pyridinium cross-link excretion. Calcium intake influences the association of protein intake with rates of bone loss in elderly men and women. Veganism, bone mineral density, and body composition: a study in Buddhist nuns Pharmacologic Treatment of Low Bone Density or Osteoporosis to Prevent Fractures: A Clinical Practice Guideline from the American College of Physicians A high ratio of dietary animal to vegetable protein increases the rate of bone loss and the risk of fracture in postmenopausal women. Study of Osteoporotic Fractures Research Group.
Dietary protein has been shown to increase urinary Ca excretion in r and omised controlled trials , and diets high in protein may have detrimental effects on bone health ; however , studies examining the relationship between dietary protein and bone health have conflicting results . In the present study , we examined the relationship between dietary protein ( total , animal and vegetable protein ) and lumbar spine trabecular volumetric bone mineral density ( vBMD ) among participants enrolled in the Multi-Ethnic Study of Atherosclerosis ( n 1658 ) .  Protein intake was assessed using a FFQ obtained at baseline examination ( 2000 - 2 ) . Lumbar spine vBMD was measured using quantitative computed tomography ( 2002 - 5 ) , on average 3 years later . Multivariable linear and robust regression techniques were used to examine the associations between dietary protein and vBMD . Sex and race/ethnicity jointly modified the association of dietary protein with vBMD ( P for interaction = 0·03 ) . Among white women , higher vegetable protein intake was associated with higher vBMD ( P for trend = 0·03 ) , after adjustment for age , BMI , physical activity , alcohol consumption , current smoking , educational level , hormone therapy use , menopause and additional dietary factors . There were no consistently significant associations for total and animal protein intakes among white women or other sex and racial/ethnic groups . In conclusion , data from the present large , multi-ethnic , population -based study suggest that a higher level of protein intake , when substituted for fat , is not associated with poor bone health . Differences in the relationship between protein source and race/ethnicity of study population s may in part explain the inconsistent findings reported previously BACKGROUND The effects of dietary protein on bone health are controversial . OBJECTIVE We examined the relation between protein intake with fracture and  bone mineral density ( BMD )  within the Women 's Health Initiative ( WHI ) . DESIGN This prospect i ve analysis included 144,580 women aged 50 - 79 y at baseline in the WHI clinical trials ( CTs ) and observational study ( OS ) that recruited participants in 1993 - 1998 with follow-up through 2011 . Self-reported clinical fractures were collected semiannually through the original end of the trials ( WHI CTs ) and annually ( WHI OS ) by question naires . Hip fracture was adjudicated by a central review of radiology reports . BMDs for total body , hip , and spine were measured at baseline and 3 and 6 y in 9062 women at 3 WHI clinics by using dual-energy X-ray absorptiometry .  Protein intake was assessed via food-frequency question naire and calibrated by using biomarkers of energy and protein intakes . Associations between protein intake and fracture were estimated by using Cox proportional hazards regression , and the relation between protein intake and BMD was estimated by using linear regression . RESULTS Median biomarker-calibrated protein intake was 15 % of energy intake . Per 20 % increase in calibrated protein intake ( percentage of energy ) , there was no significant association with total fracture ( HR : 0.99 ; 95 % CI : 0.97 , 1.02 ) or hip fracture ( HR : 0.91 ; 95 % CI : 0.84 , 1.00 ) , but there was an inverse association with forearm fracture ( HR : 0.93 ; 95 % CI : 0.88 , 0.98 ) . Each 20 % increase in calibrated protein intake was associated with a significantly higher BMD for total body ( mean 3-y change : 0.003 g/cm² ; 95 % CI : 0.001 , 0.005 g/cm² ) and hip ( mean 3-y change : 0.002 g/cm² ; 95 % CI : 0.001 , 0.004 g/cm² ) . CONCLUSIONS Higher biomarker-calibrated protein intake within the range of usual intake was inversely associated with forearm fracture and was associated with better maintenance of total and hip BMDs . These data suggest higher protein intake is not detrimental to bone health in postmenopausal women Background / Aims : The role of dietary protein in bone health is controversial . The objective of the present study was to examine the association between protein intake , dietary calcium , and bone structure measured by broadb and ultrasound attenuation ( BUA ) . Methods : Our analysis includes 8,178 female study participants of the European Prospect i ve Investigation into Cancer and Nutrition ( EPIC ) Potsdam Study . Ultrasound bone measurements were performed on the right os calcis , and BUA was determined . Dietary intake was assessed by a st and ardized food frequency question naire . We applied linear regression models to estimate the association between dietary protein and BUA . Results : After multivariate adjustment , high intake of animal protein was associated with decreased BUA values ( β = –0.03 ; p = 0.010 ) whereas high vegetable protein intake was related to an increased BUA ( β = 0.11 ; p = 0.007 ) . The effect of dietary animal protein on BUA was modified by calcium intake . Conclusion : High consumption of protein from animal origin may be unfavourable , whereas a higher vegetable protein intake may be beneficial for bone health . Our results strengthen the hypothesis that high calcium intake combined with adequate protein intake based on a high ratio of vegetable to animal protein may be protective against osteoporosis UNLABELLED The role of protein intake in osteoporosis is unclear . In a case-control study in Utah ( n = 2501 ) , increasing level of protein intake was associated with a decreased risk of hip fracture in men and women 50 - 69 years of age but not in those 70 - 89 years of age . Protein intake may be important for optimal bone health . INTRODUCTION Protein is an important component of bone , but the role of dietary protein intake in osteoporosis and fracture risk remains controversial . MATERIAL AND METHODS The role of dietary protein intake in osteoporotic hip fracture was evaluated in a statewide case-control study in Utah . Patients , 50 - 89 years of age , with hip fracture ( cases ) were ascertained through surveillance of 18 Utah hospitals during 1997 - 2001 . Age- and gender-matched controls were r and omly selected . Participants were interviewed in their place of residence , and diet was assessed using a picture-sort food frequency question naire previously reported to give a useful measure of usual dietary intake in the elderly Utah population . The association between  protein intake  and risk of hip fracture was examined across quartiles of protein intake and stratified by age group for 1167 cases ( 831 women , 336 men ) and 1334 controls ( 885 women , 449 men ) . RESULTS In logistic regression analyses that controlled for gender , body mass index , smoking status , alcohol use , calcium , vitamin D , potassium , physical activity , and estrogen use in women , the odds ratios ( OR ) of hip fracture decreased across increasing quartiles of total protein intake for participants 50 - 69 years of age ( OR : 1.0 [ reference ] ; 0.51 [ 95 % CI : 0.30 - 0.87 ] ; 0.53 [ 0.31 - 0.89 ] ; 0.35 [ 0.21 - 0.59 ] ; p < 0.001 ) . No similar associations were observed among participants 70 - 89 years of age . Results from analyses stratified by low and high calcium and potassium intake did not differ appreciably from the results presented above . CONCLUSION Higher total protein intake was associated with a reduced risk of hip fracture in men and women 50 - 69 years of age but not in men and women 70 - 89 years of age . The association between  dietary protein intake  and risk of hip fracture may be modified by age . Our study supports the hypothesis that adequate dietary protein is important for optimal bone health in the elderly 50 - 69 years of age BACKGROUND The effect of meat protein on calcium retention at different calcium intakes is unresolved . OBJECTIVE The objective was to test the effect of dietary protein on calcium retention at low and high intakes of calcium . DESIGN In a r and omized controlled feeding study with a 2 x 2 factorial crossover design , healthy postmenopausal women ( n = 27 ) consumed either approximately 675 or approximately 1510 mg Ca/d , with both low and high protein ( providing 10 % and 20 % energy ) for 7 wk each , separated by a 3-wk washout period . After 3 wk , the entire diet was extrinsically labeled with (47)Ca , and isotope retention was monitored by whole-body scintillation counting . Clinical markers of calcium and bone metabolism were measured . RESULTS High compared with low dietary protein significantly increased calcium retention from the low-calcium ( 29.5 % compared with 26.0 % absorbed ) but not the high-calcium diet ( 18 % absorbed ) . For the low-calcium diet , this effect nearly balanced a protein-related 0.5-mmol/d greater urinary calcium excretion . Protein-related calciuretic effects were independent of dietary calcium . Testing at 1 , 2 , 3 , 5 , and 7 wk showed no long-term adaptation in urinary acidity or urinary calcium excretion . High compared with low dietary protein decreased urinary deoxypyridinoline and increased serum insulin-like growth factor I without affecting parathyroid hormone , osteocalcin , bone-specific alkaline phosphatase , or tartrate-resistant acid phosphatase . CONCLUSIONS In healthy postmenopausal women , a moderate increase in dietary protein , from 10 % to 20 % of energy , slightly improved calcium absorption from a low-calcium diet , nearly compensating for a slight increase in urinary calcium excretion . Under practical dietary conditions , increased dietary protein from animal sources was not detrimental to calcium balance or short-term indicators of bone health BACKGROUND Relatively little is known about the relations between dietary patterns and bone health in adolescence , which is a period of substantial bone mass accrual . OBJECTIVES We derived dietary patterns that were hypothesized to be related to bone health on the basis of their protein , calcium , and potassium contents and investigated their prospect i ve associations with bone mineral density ( BMD ) , bone area , and bone mineral content ( BMC ) in a cohort of young adults . DESIGN The study included 1024 young adults born to mothers who were participating in the Western Australian Pregnancy Cohort ( Raine ) Study .  Dietary information was obtained from food-frequency question naires at 14 and 17 y of age . Dietary patterns were characterized according to protein , calcium , and potassium intakes with the use of reduced-rank regression . BMD , bone area , and BMC were estimated with the use of a total body dual-energy X-ray absorptiometry scan at 20 y of age . RESULTS We identified 2 major dietary patterns . The first pattern was positively correlated with intakes of protein , calcium , and potassium and had high factor loadings for low-fat dairy products , whole grains , and vegetables . The second pattern was positively correlated with protein intake but negatively correlated with intakes of calcium and potassium and had high factor loadings for meat , poultry , fish , and eggs . After adjustment for anthropometric , sociodemographic , and lifestyle factors , a higher z score for the first pattern at 14 y of age was positively associated with BMD and BMC at 20 y of age [ differences : 8.6 mg/cm(2 ) ( 95 % CI : 3.0 , 14.1 mg/cm(2 ) ) and 21.9 g ( 95 % CI : 6.5 , 37.3 g ) , respectively , per SD increase in z score ] . The z score for this same pattern at 17 y of age was not associated with bone outcomes at 20 y of age . The second pattern at 14 or 17 y of age was not associated with BMD , BMC , or bone area . CONCLUSIONS A dietary pattern characterized by high intakes of protein , calcium , and potassium in midadolescence was associated with higher BMD and BMC at 20 y of age . Our results indicate that high consumption of low-fat dairy products , whole grains , and vegetables in adolescence are associated with beneficial effects on bone development BACKGROUND Protein and alkalizing minerals are increasingly described as playing a major role in influencing bone status , not only in the elderly but also in children and adolescents . OBJECTIVE We examined whether the long-term dietary protein intake and diet net acid load are associated with bone status in children . DESIGN In a prospect i ve study design in 229 healthy children and adolescents aged 6 - 18 y , long-term dietary intakes were calculated from 3-d weighed dietary records that were collected yearly over the 4-y period before a one-time bone analysis . Dietary acid load was characterized as potential renal acid load ( PRAL ) by using an algorithm including dietary protein , phosphorus , magnesium , and potassium . Proximal forearm bone variables were measured by peripheral quantitative computed tomography . RESULTS After adjustment for age , sex , and energy intake and control for forearm muscularity , BMI , growth velocity , and pubertal development , we observed that long-term  dietary protein intake  was significantly positively associated with periosteal circumference ( P < 0.01 ) , which reflected bone modeling , and with cortical area ( P < 0.001 ) , bone mineral content ( P < 0.01 ) , and polar strength strain index ( P < 0.0001 ) , which reflected a combination of modeling and remodeling . Children with a higher dietary PRAL had significantly less cortical area ( P < 0.05 ) and bone mineral content ( P < 0.01 ) . Long-term calcium intake had no significant effect on any bone variable . CONCLUSIONS Long-term dietary protein intake appears to act anabolically on diaphyseal bone strength during growth , and this may be negated , at least partly , if dietary PRAL is high , ie , if the intake of alkalizing minerals is low Abstract It has been hypothesized that high protein intakes are associated with lower bone mineral content ( BMC ) . Previous studies yield conflicting results and thus far no studies have undertaken the interaction of body mass index ( BMI ) and physical activity with protein intakes in relation to BMC and bone mineral density ( BMD ) . Objective To evaluate the associations of dietary total protein ( TP ) , animal protein ( AP ) and plant protein ( PP ) intakes with BMC and BMD and their changes . We tested also the interactions of protein intake with , obesity ( BMI ≤30 vs. > 30 kg/m2 ) and physical activity level ( passive vs. active ) . Design / Setting Prospect i ve cohort study ( Osteoporosis Risk-Factor and Fracture-Prevention Study ) . Participants / measures At the baseline , 554 women aged 65 - 72 years filled out a 3-day food record and a question naire covering data on lifestyle , physical activity , diseases , and medications . Intervention group received calcium 1000 mg/d and cholecalciferol 800 IU for 3 years . Control group received neither supplementation nor placebo . Bone density was measured at baseline and year 3 , using dual energy x-ray absorptiometry . Multivariable regression analyses were conducted to examine the associations between protein intake and BMD and BMC . Results In cross-sectional analyses energy-adjusted TP ( P≤0·029 ) and AP ( P≤0·045 ) but not PP ( g/d ) were negatively associated with femoral neck ( FN ) BMD and BMC . Women with TP≥1·2 g/kg/body weight ( BW ) ( Ptrend≤0·009 ) had lower FN , lumbar spine ( LS ) and total BMD and BMC . In follow-up analysis , TP ( g/kg/BW ) was inversely associated with LS BMD and LS BMC . The detrimental associations were stronger in women with BMI < 30 kg/m2 . In active women , TP ( g/kg/BW ) was positively associated with LS BMD and FN BMC changes . Conclusions This study suggests detrimental associations between protein intake and bone health . However , these negative associations maybe counteracted by BMI > 30 kg/m2 and physical activity Background : Above-average dietary protein , as a single nutrient , improves musculoskeletal health . Evaluating the link between dietary protein and musculoskeletal health from a whole-diet perspective is important , as dietary guidelines focus on dietary patterns . Objective : We examined the prospect i ve association of novel dietary protein food clusters ( derived from established dietary pattern techniques ) with appendicular lean mass ( ALM ) , quadriceps strength ( QS ) , and bone mineral density ( BMD ) in 2986 men and women , aged 19 - 72 y , from the Framingham Third Generation Study . Design : Total protein intake was estimated by food-frequency question naire in 2002 - 2005 . A cluster analysis was used to classify participants into mutually exclusive groups , which were determined by using the percentage of contribution of food intake to overall protein intake . General linear modeling was used to 1 ) estimate the association between protein intake ( grams per day ) and BMD , ALM , appendicular lean mass normalized for height ( ALM/ht2 ) , and QS ( 2008 - 2011 ) and to 2 ) calculate adjusted least-squares mean outcomes across quartiles of protein ( grams per day ) and protein food clusters . Results : The mean ± SD age of subjects was 40 ± 9 y ; 82 % of participants met the Recommended Daily Allowance ( 0.8 g · kg body weight-1 · d-1 ) . The following 6 dietary protein food clusters were identified : fast food and full-fat dairy , fish , red meat , chicken , low-fat milk , and legumes  . BMD was not different across quartiles of protein intake ( P-trend range = 0.32 - 0.82 ) ; but significant positive trends were observed for ALM , ALM/ht2 ( P < 0.001 ) , and QS ( P = 0.0028 ) . Individuals in the lowest quartile of total protein intake ( quartile 1 ) had significantly lower ALM , ALM/ht2 , and QS than did those in the higher quartiles of intake ( quartiles 2 - 4 ; ( P ranges = 0.0001 - 0.003 , 0.0007 - 0.003 , and 0.009 - 0.05 , respectively ) . However , there were no associations between protein clusters and any musculoskeletal outcome in adjusted models . Conclusions : In a protein-replete cohort of adults , dietary protein is associated with ALM and QS but not with BMD . In this study , dietary protein food patterns do not provide further insight into beneficial protein effects on muscle outcomes Introduction Dietary phytochemicals are found in plant-based foods such as fruits , vegetables and grains and may be categorised in a nested hierarchical manner with many hundred individual phytochemicals identified to date . To associate phytochemical intakes with positive health outcomes , a fundamental step is to accurately estimate the dietary phytochemical intake from foods reported . The purpose of this systematic review protocol is to describe the process to be undertaken to summarise the evidence for food-based dietary phytochemical intakes and health outcomes for adults . Methods and analysis The review will be undertaken following the PRISMA guidelines and the Cochrane H and book for Systematic Review s of Interventions using the Review Manager software . Phytochemical subclasses ( phenolic acids , flavanols , etc ) will be used to search for relevant studies using the Web of Science and Scopus scientific data bases . The retrieved studies will be screened based on inclusion of natural whole food items and health outcomes . Phytochemical studies related to cardiovascular disease , cancer , overweight , glucose tolerance , digestive , reproductive , macular and bone health and mental disorders , fatigue and immunity will be examined based on prior scoping . The evidence will be aggregated by the food types and health outcomes . Comparison of differences in the outcomes for r and omised controlled trials and observational studies will be undertaken . The strength of the review lies in its focus on whole food items and health conditions rather than one type of phytochemical related to one single health condition . Subgroup and sensitivity analyses will be conducted where an adequate number of publications are found per phytochemical subclass . Dissemination By comparing the outcomes from experimental and observational studies , the review will determine whether the overall conclusions related to the phytochemical subclasses are the same between study types for the identified health conditions . This is useful to public health policymakers and health professionals alike . Trial registration number # CRD42014015610 BACKGROUND Controversy exists concerning the effects of higher total protein intake ( TPro ) on bone health , which may be associated with reduced bone mineral density ( BMD ) . However , whey protein ( WP ) may induce bone formation because of its basic component , milk basic protein . OBJECTIVE This study assessed the effects of WP supplementation , TPro , and change in TPro ( postsupplementation - presupplementation ) on BMD and bone mineral content ( BMC ; total body , lumbar spine , total femur , and femoral neck ) in overweight and class I obese middle-aged adults following an exercise intervention . METHODS This analysis used data from a double-blind , r and omized , placebo-controlled 36-wk WP supplementation trial , wherein participants consumed a 1.7-MJ ( 400-kcal ) supplement ( 0 , 20 , 40 , or 60 g WP/d ) along with their otherwise unrestricted diet while participating in a resistance and aerobic exercise intervention ( 3 d/wk ) . TPro was the summation of WP and habitual dietary intakes ( 4-d food record ) . Statistical analyses for WP were based on group and bone data [ n = 186 , 108 women ; mean ± SD age : 49 ± 8 y ; body mass index ( BMI ; in kg/m2 ) : 30.1 ± 2.8 ] , whereas TPro was based on dietary and bone data ( n = 113 , 70 women ; age 50 ± 8 y ; BMI 30.1 ± 2.9 ) . RESULTS WP supplementation , regardless of dose , did not influence BMD or BMC following the intervention . By using a multiple linear regression model , TPro ( expressed as g/d or g · kg-1 · d-1 ) and change in TPro ( expressed as g/d ) were not associated with responses over time in total or regional BMD or BMC . By using a cluster analysis approach [ < 1.0 ( n = 41 ) , 1.0 - 1.2 ( n = 28 ) , and ≥1.2 g · kg-1 · d-1 ( n = 44 ) ] , TPro was also not associated with responses in total or regional BMD or BMC over time . CONCLUSION WP supplementation and total dietary protein intake did not negatively or beneficially influence bone quantity in overweight and obese adults during a 9-mo exercise intervention . This trial was registered at clinical trials.gov as NCT00812409 One of the main focuses of lifestyle modification for the prevention of osteoporosis and osteoporotic fractures  in Japan is improvement in dietary calcium intake . However , virtually no r and omized controlled trial to assess the preventive effects of administration of calcium on the risk of fractures has been conducted in Japan . In this study , we review ed all the scientific papers currently available from medical literature data bases to propose evidence -based recommendations on the preventive procedures for osteoporosis . The result of the present systematic review gives the evidence showing that calcium supplementation or optimal dietary calcium intake increases bone density in childhood and adolescence and reduces the risk of fracture due to osteoporosis in the elderly people regardless of the gender . The evidence also supports the current health policy guiding the elderly to increase their dietary calcium intake in daily life PURPOSE Health interventions based on theory may be more effective than those that are not . This review of review s synthesizes all published r and omized controlled trial ( RCT ) meta-analytic evidence from the last decade to examine whether theory-based interventions were found to be associated with more effective  adult health behaviour change interventions . METHODS Systematic review s including meta-analyses were identified by search ing Medline , CINAHL , PsycINFO , and CDSR . A narrative synthesis was used to summarize and analyse the evidence . Only review s including RCTs of health behaviour change interventions with adults aged 18 + published from 2007 to 2017 were included . RESULTS Of 8,659 articles , nine systematic review s met inclusion criteria . The majority of review s ( n = 8) suggested no increased effectiveness for theory-based compared to non-theory-based interventions for effectiveness of outcomes relating to health behaviour . Less than half of the RCTs included in the review s reported the use of theory ( 85/183 ) . Two review s suggested interventions based on control theory , motivational interviewing , or self-determination theory were associated with greater effectiveness for physical activity and /or dietary interventions and outcomes . Method ological and reporting issues limit the conclusions . CONCLUSIONS Theory-based interventions as currently operationalized in systematic review s were not found to be more effective than non-theory-based interventions . Method ological and reporting issues at study and review level may not reflect the true utility of theory use within health behaviour interventions . The promotion of theory use may benefit from using a multifaceted argument , rather than a narrow focus of increased effectiveness . Statement of contribution What is already known on this subject ? Theory use is regularly promoted by cl aim ing that it will lead to more effective behaviour change interventions . Theory use has been frequently linked to effectiveness within systematic review s of behaviour change interventions . The theory-effectiveness hypothesis has not been systematic ally examined at the systematic review level . What does this study add ? Theory use as operationalized by systematic review authors was not associated with increased effectiveness within systematic review s examining r and omized controlled trials of behaviour change interventions in adults . Interventions based on control theory , motivational interviewing , or self-determination theory were associated with greater effectiveness for physical activity and /or dietary interventions and outcomes . Theory use should be promoted using a multifaceted argument , and assertions for increased effectiveness of theory-based interventions should only be used in domains where specific evidence exists to support this cl aim Abstract : Lifestyle factors , such as diet , are believed to be involved in modifying bone health , although the results remain controversial , particularly in children and adolescents . The objective of the study was to identify associations between dietary factors and whole body bone measurements in 10-year-old children . The study was a cross-sectional analysis of a r and om sample of 105 healthy Danish children , aged 10 years ( 9.97 ± 0.09 ) . Whole body bone mineral content ( BMC ) and bone area ( BA ) were determined by dual-energy X-ray absorptiometry . The influence of diet ( 7 day food records ) on BMC and BA were examined in bi- and multivariate analyses . The mean intakes of calcium , protein , phosphorus and sodium were 1226 mg , 78 g , 1523 mg and 3.3 g , respectively . In bivariate analyses , BMC and BA were strongly positively correlated with height ( p<0.001 ) and weight ( p<0.001 ) , and with intakes of energy ( p<0.005 ) and several nutrients . BMC was adjusted for size by including BA , height and weight in the multiple linear regression , and BA was adjusted for size by including height and weight in the multiple linear regression . In multivariate analyses , size-adjusted BMC was positively associated with calcium intake ( p = 0.02 ) . Size-adjusted BA was positively associated with dietary protein ( p = 0.003 ) , and negatively associated with intakes of sodium ( p = 0.048 ) and phosphorus ( p = 0.01 ) . In conclusion , calcium intake was positively associated with bone mineralization . There was a positive association between protein and BA , while for phosphorus and sodium the association was negative . The findings suggest that in addition to calcium , the intake of other nutrients influences bone development in prepubertal children Background Calcium ( Ca ) is an essential nutrient for the human body . Despite lively research , there is uncertainty about Ca requirements in terms of desirable health outcomes including an upper intake level above which the potential for harm increases . Objectives The aim was to conduct a review to up date requirements and desirable or harmful health effects of Ca on the current scientific evidence . Methods We search ed Medline and Swemed from January 2000 to December 2011 and included all systematic review s that reported Ca supplementation or usual Ca intake on health outcomes . Meta-analyses , r and omized clinical trials and cohort studies were included in the second search between May 2009 and March 2011 and an additional search covering studies till the end of 2011 . This review concentrated on studies reporting independent effects of Ca , although a few recent trials report sole effects of Ca on health outcomes , most trials use Ca in combination with vitamin D vs. placebo . Results In total , we review ed 38 studies addressing the effects of Ca on bone , pregnancy-related outcomes , cancers , cardiovascular outcomes , obesity , and mortality .  There was a lot of heterogeneity in the study protocol s , which made it difficult to draw any strong conclusions . According to the literature , high Ca intake seems to have a small positive effect on bone mineral content ( BMC ) or bone mineral density ( BMD ) in children and postmenopausal women . We did not find any consistent evidence on the effects of Ca on bone health in premenopausal women or men . Also , the evidence that Ca supplementation reduces fracture incidence is scarce and inconsistent . Maternal diet may influence the peak bone mass of offspring but more studies are required . There was no overall effect of Ca intake on cancers . Ca was associated with a decreased risk of breast cancer and a slightly increased risk of prostate cancer in two of the three studies . No associations were found with other cancers . We found no consistent association between cardiovascular outcomes and  Ca  intake except for blood pressure . A small decrease of 2–4 mmHg in systolic blood pressure was found in pregnant and in hypertensive subjects with Ca supplementation . Review ed studies did not show consistent evidence relating Ca intake to either mortality or obesity . Conclusion Based on this evidence , there is no need to change the Nordic recommendations for Ca intake . However , due to heterogeneity in the studies it is difficult to interpret the results and provide single summary statement Currently there is no consensus on the impact of dietary protein on calcium and bone metabolism . This study was conducted to examine the effect of increasing protein intake on urinary calcium excretion and to compare circulating levels of IGF-I and biochemical markers of bone turnover in healthy older men and women who consumed either a high or a low protein food supplement for 9 wk . Thirty-two subjects with usual protein intakes of less than 0.85 g/kg.d were r and omly assigned to daily high ( 0.75 g/kg ) or low ( 0.04 g/kg ) protein supplement groups . Isocaloric diets were maintained by advising subjects to reduce their intake of carbohydrates . Selected biochemical measurements were made at baseline and on d 35 and either d 49 or 63 . Changes in urinary calcium excretion in the two groups did not differ significantly over the course of the study . The high protein group had significantly higher levels of serum IGF-I ( P = 0.008 ) and lower levels of urinary N-telopeptide ( P = 0.038 ) over the period of d 35 - 49 or 63 . We conclude that increasing protein intake from 0.78 to 1.55 g/kg.d with meat supplements in combination with reducing carbohydrate intake did not alter urine calcium excretion , but was associated with higher circulating levels of IGF-I , a bone growth factor , and lowered levels of urinary N-telopeptide , a marker of bone resorption . In contrast to the widely held belief that increased protein intake results in calcium wasting , meat supplements , when exchanged isocalorically for carbohydrates , may have a favorable impact on the skeleton in healthy older men and women 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 BACKGROUND Skeletal loading and proper nutrition are necessary for optimal bone health . The appropriate amount of dietary protein to maximize skeletal health , however , is under constant debate . OBJECTIVE To determine if 6 months of protein supplementation in conjunction with a strength and conditioning training program improves areal and volumetric bone mineral density ( BMD ) . DESIGN Fifty-two apparently healthy males and females ages 18 - 25 years were r and omized to protein supplement ( PRO , Myoplex , EAS , Inc. Golden CO ) containing 280 kcal , 42 g protein , 21 g carbohydrate , and 1.5 g fat ) or calorically equivalent carbohydrate control ( CS ) . All subjects participated in a 5 sessions/week strength and conditioning program .  Volumetric and areal BMD measurements were made by peripheral quantitative computed tomography ( pQCT ) of the tibia and whole body DXA . pSSI a measure of torsional bone strength , based on structural and material properties was obtained by pQCT . RESULTS Measurements at the 20 % tibia by pQCT revealed that overall there were significant increases in cortical vBMD ( 4.3 + /- 1.3 mg/cm(3 ) ) , cortical area ( 1.9 + /- 0.6 cm(2 ) ) , cortical thickness ( 0.05 + /- 0.02 mm ) and pSSI ( 67 + /- 24 mm(3 ) ) , and a decrease in endosteal circumference ( - 0.5 + /- 0.2 mm ) over the intervention period ( all , P < 0.05 ) . None of the changes in DXA measures were found to differ by group or sex , there was a trend for a greater increase in whole body BMC among the carbohydrate compared to protein supplemented group and a greater increase among males ( 16 + /- 8 g ) compared to females ( -9 + /- 9 g ) ( P = 0.06 ) . CONCLUSIONS The results of this study indicate that the consumption of additional protein does not improve measurements of vBMD or bone size during a 6-month strength and conditioning program . Longer duration studies may be necessary to determine the influence of increased dietary protein on bone in young adults . Males and females may have different bone responses to increased protein intake while participating in a strength and conditioning program This study was conducted to determine whether the markers of bone resorption , pyridinium cross-links of collagen , are sensitive to changes in dietary protein and calcium intake . Fifteen young healthy subjects ( 7 males and 8 females ) participated in three 5-d diet periods . Dietary intake during each dietary period consisted of : 1 ) low nitrogen and low calcium [ 0.49 + /- 0.11 g protein/ ( kg.d ) , 429 + /- 190 mg calcium/d ] ; 2 ) low nitrogen and high calcium [ 0.44 + /- 0.08 g protein/(kg.d ) , 1643 + /- 171 mg calcium/d ] ; and 3 ) a high nitrogen and high calcium [ 2.71 + /- 0.75 g protein/(kg.d ) , 1589 + /- 633 mg calcium/d ] diet , and this was compared with subjects ' baseline dietary intake [ 0.99 + /- 0.51 g protein/(kg.d ) , 589 + /- 152 mg calcium/d ] . The order of these diets was r and omly assigned . Twenty-four-hour and 3-h urine sample s were collected before and during each dietary period and were analyzed for pyridinium cross-links ( pyridinoline , deoxypyridinoline ) , nitrogen and creatinine . The rate of pyrdinium cross-link excretion did not vary with protein intake but was approximately 33 % lower ( P < 0.01 ) during periods of high compared with low calcium intake . These data indicate that a short-term increase in calcium intake is accompanied by a reduced rate of bone resorption and that this effect is independent of dietary protein intake BACKGROUND There is currently no consensus on the effect of dietary protein intake on the skeleton , but there is some indication that low calcium intakes adversely influence the effect of dietary protein on fracture risk . OBJECTIVE The objective of the present study was to determine whether supplemental calcium citrate malate and vitamin D influence any associations between  protein intake and change in bone mineral density ( BMD ) . DESIGN Associations between protein intake and change in BMD were examined in 342 healthy men and women ( aged > or = 65 y ) who had completed a 3-y , r and omized , placebo-controlled trial of calcium and vitamin D supplementation . Protein intake was assessed at the midpoint of the study with the use of a food-frequency question naire and  BMD  was assessed every 6 mo by dual-energy X-ray absorptiometry . RESULTS The mean ( + /-SD ) protein intake of all subjects was 79.1 + /- 25.6 g/d and the mean total calcium intakes of the supplemented and placebo groups were 1346 + /- 358 and 871 + /- 413 mg/d , respectively . Higher protein intake was significantly associated with a favorable 3-y change in total-body BMD in the supplemented group ( in a model containing terms for age , sex , weight , total energy intake , and dietary calcium intake ) but not in the placebo group . The pattern of change in femoral neck BMD with increasing protein intake in the supplemented group was similar to that for the total body . CONCLUSION Increasing protein intake may have a favorable effect on change in BMD in elderly subjects supplemented with calcium citrate malate and vitamin Summary This cross-sectional study showed that , although vegans had lower dietary calcium and protein intakes than omnivores , veganism did not have adverse effect on bone mineral density and did not alter body composition . Introduction Whether a lifelong vegetarian diet has any negative effect on bone health is a contentious issue . We undertook this study to examine the association between lifelong vegetarian diet and bone mineral density and body composition in a group of postmenopausal women . Methods One hundred and five Mahayana Buddhist nuns and 105 omnivorous women ( average age = 62 , range = 50–85 ) were r and omly sample d from monasteries in Ho Chi Minh City and invited to participate in the study . By religious rule , the nuns do not eat meat or seafood ( i.e. , vegans ) . Bone mineral density ( BMD ) at the lumbar spine ( LS ) , femoral neck ( FN ) , and whole body ( WB ) was measured by DXA ( Hologic QDR 4500 ) . Lean mass , fat mass , and percent fat mass were also obtained from the DXA whole body scan . Dietary calcium and protein intakes were estimated from a vali date d food frequency question naire . Results There was no significant difference between vegans and omnivores in LSBMD ( 0.74 ± 0.14 vs. 0.77 ± 0.14 g/cm2 ; mean ± SD ; P = 0.18 ) , FNBMD ( 0.62 ± 0.11 vs. 0.63 ± 0.11 g/cm2 ; P = 0.35 ) , WBBMD ( 0.88 ± 0.11 vs. 0.90 ± 0.12 g/cm2 ; P = 0.31 ) , lean mass ( 32 ± 5 vs. 33 ± 4 kg ; P = 0.47 ) , and fat mass ( 19 ± 5 vs. 19 ± 5 kg ; P = 0.77 ) either before or after adjusting for age . The prevalence of osteoporosis ( T scores ≤ −2.5 ) at the femoral neck in vegans and omnivores was 17.1 % and 14.3 % ( P = 0.57 ) , respectively . The median intake of dietary calcium was lower in vegans compared to omnivores ( 330 ± 205 vs. 682 ± 417 mg/day , P < 0.001 ) ; however , there was no significant correlation between dietary calcium and BMD . Further analysis suggested that whole body BMD , but not lumbar spine or femoral neck BMD , was positively correlated with the ratio of animal protein to vegetable protein . Conclusion These results suggest that , although vegans have much lower intakes of dietary calcium and protein than omnivores , veganism does not have adverse effect on bone mineral density and does not alter body composition The National Institutes of Health 's consensus conference ( 1 ) defined osteoporosis as a skeletal disorder characterized by compromised bone strength predisposing to an increased risk for fracture . Bone strength reflects the integration of two main features : bone density and bone quality .Bone quality refers to architecture , turnover , damage accumulation ( e.g. , microfractures ) , and mineralization . Although osteoporosis can affect any bone , the hip , spine , and wrist are most likely to be affected . Osteoporosis affects an estimated 44 million Americans or 55 % of people 50 years of age or older . Another 34 million Americans are estimated to have low bone mass , meaning that they are at an increased risk for osteoporosis . Osteoporosis can be diagnosed by the occurrence of fragility fracture . In patients without fragility fracture , osteoporosis is often diagnosed by low bone density .  Dual x-ray absorptiometry ( DXA ) is the current gold st and ard test for diagnosing osteoporosis in people without an osteoporotic fracture .  Dual x-ray absorptiometry results are scored as st and ard deviations ( SDs ) from a young healthy norm ( usually female ) and reported as T-scores . For example , a T-score of 2 indicates a bone mineral density that is 2 SDs below the comparative norm . The international reference st and ard for the description of osteoporosis in postmenopausal women and in men age 50 years or older is a femoral neck bone mineral density of 2.5 SD or more below the young female adult mean ( 2 ) . Low bone density , as measured by DXA , is an imperfect predictor of fracture risk , identifying fewer than half the people who go on to have an osteoporotic fracture . Screening guidelines for women are well established ( 3 ) , and the American College of Physicians ( ACP ) recently published guidelines on screening for men ( 4 ) . This guideline presents the available evidence on various pharmacologic treatments to prevent fractures in men and women with low bone density or osteoporosis . Medications used to treat osteoporosis may affect different parts of the skeletal system differently , and efficacy for vertebral fractures does not necessarily imply efficacy for nonvertebral fractures . The target audience for this guideline is all clinicians and the target patient population is all adult men and women with low bone density or osteoporosis . These recommendations are based on the systematic evidence review by MacLean and colleagues ( 5 ) and the Agency for Healthcare Research and Quality sponsored Southern California Evidence -Based Practice Center evidence report ( 6 ) . The drugs currently approved for prevention of osteoporosis include alendronate , ib and ronate , risedronate , zoledronic acid , estrogen , and raloxifene . The drugs currently approved for treatment of osteoporosis include alendronate , ib and ronate , risedronate , calcitonin , teriparatide , zoledronic acid ( in postmenopausal women ) , and raloxifene . Testosterone , pamidronate , and etidronate are not approved by the U.S. Food and Drug Administration for the treatment or prevention of osteoporosis . Methods The literature search done by MacLean and colleagues for the systematic review ( 5 ) included studies from MEDLINE ( 1966 to December 2006 ) , the ACP Journal Club data base , the Cochrane Central Register of Controlled Trials ( no date limits ) , the Cochrane Data base of Systematic Review s ( no date limits ) , Web sites of the United Kingdom National Institute of Health and Clinical Excellence ( no date limits ) , and the United Kingdom Health Technology Assessment Program ( January 1998 to December 2006 ) . The review ers limited their search to English- language publications and human studies . They derived evidence for comparative benefits of various treatments exclusively from r and omized , controlled trials , whereas they included evidence from other types of studies for short- and long-term harms . Two physicians independently abstract ed data about study population s , interventions , follow-up , and outcome ascertainment by using a structured form . For each group within a r and omized trial , a statistician extracted the sample size and number of persons reporting fractures . Two review ers , under the supervision of the statistician , independently abstract ed information about adverse events . The statistician or the principal investigator resolved disagreements . This guideline is based on an evaluation of 76 r and omized , controlled trials , 4 of which were identified in the up date d search , and 24 meta-analyses that were included in the efficacy analyses . The analyses of adverse events included 491 articles , representing 417 r and omized trials , 25 other controlled clinical trials , 11 open-label trials , 31 large observational studies , and 9 case reports of osteonecrosis among bisphosphonate users . MacLean and colleagues ' background article ( 5 ) includes details about the methods used for the systematic evidence review . The ACP rates the evidence and recommendations by using the Grading of Recommendations , Assessment , Development , and Evaluation ( GRADE ) system with minor modifications ( Table 1 ) . In addition , the evidence review ers used predefined criteria to assess the quality of systematic review s and r and omized trials , based on internal and external validity assessment s detailed in the Quality of Reporting of Meta-Analyses ( QUOROM ) statement ( 7 ) . Table 1 . The American College of Physicians ' Guideline Grading System The objective of this guideline is to synthesize the evidence for the following questions : What are the comparative benefits in fracture reduction among and also within the following treatments for low bone density :  bisphosphonates , specifically alendronate , risedronate , etidronate , ib and ronate , pamidronate , and zoledronic acid ; calcitonin ; estrogen for women ; teriparatide ; selective estrogen receptor modulators ( SERMs ) , specifically raloxifene and tamoxifen ; testosterone for men ; vitamins and minerals , specifically vitamin D and calcium ; and the combination of calcium plus vitamin D ? How does fracture reduction result ing from treatments vary among individuals with different risks for fracture as determined by bone mineral density ( borderline , low , or severe ) , previous fractures ( prevention vs. treatment ) , age , sex , glucocorticoid use , and other factors ( such as community-dwelling vs. institutionalized or vitamin Ddeficient vs. not ) ? What are the short- and long-term harms ( adverse effects ) of these therapies , and do these vary by specific sub population s ? Comparative Benefits of Drugs versus Placebo in Fracture Reduction Evidence from 24 meta-analyses ( 830 ) and 35 additional r and omized trials published after the meta-analyses ( 3165 ) described the effect of 9 of the 14 agents ( alendronate , etidronate , risedronate , calcitonin , estrogen , teriparatide , raloxifene , calcium , and vitamin D ) on fracture incidence . For 4 agents ( ib and ronate , pamidronate , zoledronic acid , and tamoxifen ) , the review ers found no meta-analyses and instead gathered the evidence from 14 r and omized trials ( 6679 ) . No studies were found that reported fracture rates for testosterone . Three r and omized trials ( 35 , 80 , 81 ) and 1 meta- analysis ( 82 ) evaluated the combination of calcium plus vitamin D  on fractures .  Bisphosphonates Good- quality evidence showed that alendronate , etidronate , ib and ronate , and risedronate prevent vertebral fractures . In addition , evidence from good- quality studies demonstrated that both alendronate and risedronate prevent nonvertebral and hip fractures . Two large r and omized trials showed that zoledronic acid prevents vertebral and nonvertebral fractures in high-risk population s and reduces the risk for hip fracture ( 67 , 74 ) . Ib and ronate has not been shown to reduce nonvertebral fractures ( 68 ) . Of the 6 fairly small trials that looked at vertebral fractures , 1 demonstrated a statistically significant reduction in fractures with pamidronate relative to placebo ( 0.14 [ 95 % CI , 0.03 to 0.72 ] ) ( 73 ) . However , after these data were pooled , the pooled risk estimate for fractures for pamidronate relative to placebo was not significant ( 0.52 [ CI , 0.21 to 1.24 ] ) ( 6 ) . Calcitonin Fair- quality evidence shows that calcitonin reduces vertebral fractures ( 83 , 84 ) . Good- quality evidence indicates that calcitonin does not reduce nonvertebral fractures ( 13 , 16 ) . Estrogen Good- quality evidence shows that estrogen reduces the incidence of vertebral ( 29 , 85 ) , nonvertebral ( 86 ) , and hip fractures ( 85 ) . Teriparatide Good- quality evidence shows that teriparatide prevents vertebral fractures . The evidence related to teriparatide preventing nonvertebral fractures is mixed ; 1 large r and omized trial showed a reduction in nonvertebral fractures ( 34 ) but 2 small trials did not ( 87 , 88 ) . SERMs Good- quality evidence shows that raloxifene prevents vertebral fractures , but that tamoxifen has no effect on vertebral fractures ( 8991 ) . In addition , both raloxifene and tamoxifen had no effect on hip fractures ( 91 ) . Tamoxifen is not approved by the U.S. Food and Drug Administration for the treatment or prevention of osteoporosis . Testosterone No studies reported fracture rates for testosterone . Calcium and Vitamin D In the studies evaluated by MacLean and colleagues ( 5 ) , the evidence for the effect of calcium alone on reduction of fractures is complex . Most studies of pharmacologic agents for osteoporosis include calcium and vitamin D as part of the treatment regimen . Evidence from 1 meta- analysis ( 27 ) and several r and omized trials ( 35 , 48 , 51 , 92 ) showed no significant difference between calcium and placebo in preventing vertebral , nonvertebral , and hip fractures in postmenopausal women . However , nonadherence to therapy may influence this result , and 1 trial with a prespecified analysis of adherent patients found a reduction in fracture risk ( 48 ) . A recent meta- analysis ( 82 ) concluded that the relative risk ( RR ) for fracture with calcium alone was 0.90 ( CI , 0.80 to 1.00 ) , but it did not include a modestly large trial with negative results ( 35 ) . MacLean and colleagues ( 5 ) BACKGROUND Different sources of dietary protein may have different effects on bone metabolism . Animal foods provide predominantly acid precursors , whereas protein in vegetable foods is accompanied by base precursors not found in animal foods . Imbalance between dietary acid and base precursors leads to a chronic net dietary acid load that may have adverse consequences on bone . OBJECTIVE We wanted to test the hypothesis that a high dietary ratio of animal to vegetable foods , quantified by protein content , increases bone loss and the risk of fracture . DESIGN This was a prospect i ve cohort study with a mean ( + /-SD ) of 7.0+/-1.5 y of follow-up of 1035 community-dwelling white women aged > 65 y.  Protein intake  was measured by using a food-frequency question naire and  bone mineral density was measured by dual-energy X-ray absorptiometry . RESULTS Bone mineral density was not significantly associated with the ratio of animal to vegetable protein intake . Women with a high ratio had a higher rate of bone loss at the femoral neck than did those with a low ratio ( P = 0.02 ) and a greater risk of hip fracture ( relative risk = 3.7 , P = 0.04 ) . These associations were unaffected by adjustment for age , weight , estrogen use , tobacco use , exercise , total calcium intake , and total protein intake . CONCLUSIONS Elderly women with a high dietary ratio of animal to vegetable protein intake  have more rapid femoral neck bone loss and a greater risk of hip fracture than do those with a low ratio . This suggests that an increase in vegetable protein intake and a decrease in animal protein intake may decrease bone loss and the risk of hip fracture . This possibility should be confirmed in other prospect i ve studies and tested in a r and omized trial
There appears to be little benefit of increasing protein intake for bone health in healthy adults but there is also clearly no indication of any detrimental effect , at least within the protein intakes of the population s studied ( around 0.8–1.3 g/Kg/day ) .
We undertook a systematic review and meta- analysis of published papers assessing  dietary protein and bone health .
We found little benefit of increasing protein intake for  bone health in healthy adults but no indication of any detrimental effect , at least within the protein intakes of the population s studied .
This systematic review and meta- analysis analysed the relationship between dietary protein and bone health across the life-course .