Effect of calcium supplementation on bone mineral accretion in gambian children accustomed to a low-calcium diet. Cumulative effects of calcium supplementation and physical activity on bone accretion in premenarchal children: a double-blind randomised placebo-controlled trial. Calcium supplementation and bone mineral density in females from childhood to young adulthood: a randomized controlled trial. Bone mass and density response to a 12-month trial of calcium and vitamin D supplement in preadolescent girls. The effects of a high calcium dairy food on bone health in pre-pubertal children in New Zealand. Effects of dairy food supplements on bone mineral density in teenage girls A randomized controlled trial of vitamin D3 supplementation in African American women. The effects of calcium supplementation and exercise on bone density in elderly Chinese women The effect on behavior and bone mineral density of individualized bone mineral density feedback and educational interventions in premenopausal women: a randomized controlled trial [NCT00273260] Vitamin D supplementation and bone mineral density in early postmenopausal women. Effect of withdrawal of calcium and vitamin D supplements on bone mass in elderly men and women. Factors affecting bone density in young adults. Reduced rates of skeletal remodeling are associated with increased bone mineral density during the development of peak skeletal mass. Skeletal site-dependent response of bone mineral density and quantitative ultrasound parameters following a 12-month dietary intervention using dairy products fortified with calcium and vitamin D: the Postmenopausal Health Study. Bone mineral contents and plasma osteocalcin concentrations of Gambian children 12 and 24 mo after the withdrawal of a calcium supplement. A two-year program of aerobics and weight training enhances bone mineral density of young women. Increased periosteal circumference remains present 12 months after an exercise intervention in preschool children. Calcium-enriched foods and bone mass growth in prepubertal girls: a randomized, double-blind, placebo-controlled trial. Effect of a general school-based physical activity intervention on bone mineral content and density: a cluster-randomized controlled trial. Calcium intake influences the association of protein intake with rates of bone loss in elderly men and women. Calcium supplementation provides an extended window of opportunity for bone mass accretion after menarche. Prediction of bone mass density variation by bone remodeling markers in postmenopausal women with vitamin D insufficiency treated with calcium and vitamin D supplementation. Bone mineralization in children and adolescents with a milk allergy.
BACKGROUND Rural Gambian children have poor growth , delayed puberty , a low bone mineral content , and a low calcium intake . OBJECTIVE We investigated the effect of a calcium supplement on bone mineral accretion in rural Gambian children . DESIGN A r and omized , double-blind , placebo-controlled study was conducted in 160 children ( 80 boys , 80 girls ) aged 8.3 - 11.9 y.  Bone mineral content ( BMC ) , bone mineral density ( BMD ) , and BMC adjusted for bone width , body weight , and height ( size-adjusted BMC ) were measured at the midshaft and distal radius . Each child received either 1000 mg Ca/d ( as calcium carbonate ) or a placebo 5 d/wk for 12 mo . Supplementation increased calcium intake from 342 to 1056 mg/d ( 8.6 to 26.4 mmol/d ) . RESULTS Calcium supplementation result ed in a higher BMC , BMD , and size-adjusted BMC ( & xmacr ; difference + /- SE ) : midshaft radius- BMC ( 3.0 + /- 1.4 % ; P = 0.034 ) , BMD ( 4.5 + /- 0.9 % ; P < /= 0.0001 ) , and size-adjusted BMC ( 4.6 + /- 0.9 % ; P < /= 0.0001 ) ; distal radius- BMC ( 8 . 4 + /- 3.2 % ; P = 0.009 ) , BMD ( 7.0 + /- 2.7 % ; P = 0.011 ) , and size-adjusted BMC ( 5.5 + /- 2.7 % ; P = 0.042 ) . Supplementation had no significant effect on height , weight , or bone width at the midshaft radius or distal radius . At the end of the study , the calcium group had a significantly lower mean plasma osteocalcin concentration than the placebo group after adjustment for baseline concentration , sex , and pubertal status ( -21.9 + /- 6.5 % ; P = 0.001 ) . CONCLUSIONS Increased calcium intake result ed in increased bone mineral status , possibly in association with a decreased bone remodeling space . Further studies are needed to determine whether an increased calcium intake has long-term benefits in Gambian children High calcium intake combined with physical activity during childhood have been shown to improve bone mass accrual and bone mineral density . Our aim was to study the combined effect of calcium and exercise on  bone gain in children . Two milk-powder products containing either 800 mg of calcium phosphate ( calcium ) or not ( placebo ) were r and omly allocated to 113 healthy premenarchal girls on a daily basis for 1 year . The group was composed of 63 exercise ( 7.2 + /- 4 hours of exercise/week ) and 50 sedentary ( 1.2 + /- 0.8 hours of exercise/week ) children . The final experiment had 4 groups : exercise/calcium ( n = 12 ) , exercise/placebo ( n = 42 ) , sedentary/calcium ( n = 10 ) , and sedentary/placebo ( n = 21 ) . Bone mineral density ( BMD ) at 6 skeletal sites and body composition were determined by DXA . Bone age was calculated and the daily spontaneous calcium intake was assessed by a frequency question naire . All the tests were performed at baseline and 1 year by the same observer . BMD gains were significantly greater in the exercise/calcium group than in other groups at the total body ( increase of 6.3 % , p < 0.05 ) , lumbar spine ( 11 % , p < 0.05 ) , femoral neck ( 8.2 % , p < 0.02 ) , and Ward 's triangle ( 9.3 % , p < 0.01 ) . There was no difference between the other groups . These data suggest that calcium supplementation increases the effect of physical exercise on bone mineral acquisition in the period preceding puberty , and that calcium supplementation without physical activity does not improve the BMD acquisition during this period . Physical exercise that stimulates bone accretion needs a high calcium intake to be completely effective BACKGROUND Short-term studies established that calcium influences bone accretion during growth . Whether long-term supplementation influences bone accretion in young adults is not known . OBJECTIVE This study evaluated the long-term effects of calcium supplementation on bone accretion among females from childhood to young adulthood . DESIGN A 4-y r and omized clinical trial recruited 354 females in pubertal stage 2 and optionally was extended for an additional 3 y. The mean dietary calcium intake of the participants over 7 y was approximately 830 mg/d ;  calcium-supplemented persons received an additional approximately 670 mg/d . Primary outcome variables were distal and proximal radius bone mineral density ( BMD ) , total-body BMD ( TBBMD ) , and metacarpal cortical indexes . RESULTS Multivariate analyses of the primary outcomes indicated that  calcium-supplementation  effects vary over time . Follow-up univariate analyses indicated that all primary outcomes were significantly larger in the supplemented group than in the placebo group at the year 4 endpoint . However , at the year 7 endpoint , this effect vanished for TBBMD and distal radius BMD . Longitudinal models for TBBMD and proximal radius BMD , according to the time since menarche , showed a highly significant effect of supplementation during the pubertal growth spurt and a diminishing effect thereafter . Post hoc stratifications by compliance-adjusted total calcium intake and by final stature or metacarpal total cross-sectional area showed that calcium effects depend on compliance and body frame . CONCLUSIONS Calcium supplementation significantly influenced bone accretion  in young females during the pubertal growth spurt . By young adulthood , significant effects remained at metacarpals and at the forearm of tall persons , which indicated that the calcium requirement for growth is associated with skeletal size . These results may be important for both primary prevention of osteoporosis and prevention of bone fragility fractures during growth BACKGROUND Maximal bone acquisition in adolescent girls through dietary and lifestyle practice s is advocated to prevent or minimize the development of osteoporosis and its associated complications in later life . Longitudinal investigations of bone acquisition in children and adolescents have utilized areal bone mineral density ( BMD , mg/cm(2 ) ) as a measure of bone mass and strength . Peripheral quantitative computed tomography ( pQCT ) , which provides a three-dimensional display of data , separate analyses of bone compartments , and bone mass in terms of volumetric BMD ( vBMD , mg/cm(3 ) ) , has recently been introduced for clinical use . OBJECTIVE To assess the impact of a 12-month daily calcium supplement on total and trabecular bone acquisition as measured by pQCT in preadolescent girls . DESIGN Early adolescent Caucasian girls ( aged 12 years , Tanner Stage 2 ) were enrolled in a r and omized trial of daily calcium supplement ( TX , 800 mg calcium carbonate and 400 IU vitamin D ) or placebo ( C ) . Body weight , height , and distal tibia measurements by pQCT were obtained at enrollment , 6 and 12 months . Pubertal status and physical activity records were assessed at baseline and 12 months . Three-day food intake records were completed every three months . RESULTS Seventy-one girls completed the 12-month trial ( TX=35 , C=36 ) . No differences were found for age , weight , height , body mass index , pubertal maturation , or reported physical activity at enrollment or during the study . Average intakes during the study were 1524 mg calcium and 496 IU vitamin D ( TX ) versus 865 mg calcium and 160 IU vitamin D ( C ) per day . Baseline total bone values were similar , however , trabecular values were greater in TX girls despite r and omization . Percent changes were calculated to adjust for baseline differences . Because of the small cortical thickness at the 10 % site ( mean values < 1.6 mm ) , cortical mass and density were not analyzed . The percent changes for trabecular bone mineral content ( BMC , mg ) and vBMD were significantly greater in TX girls ( + 4.1 % BMC and + 1.0 % vBMD TX versus -1.6 % BMC and -2.0 % vBMD C , p<0.006 ; ANCOVA ) after 12 months of supplement . Trabecular bone area ( BA , cm(2 ) ) and total bone change , however , did not differ between groups . CONCLUSIONS Daily calcium and vitamin D supplementation promotes greater trabecular BMC and vBMD acquisition in preadolescent girls . The single site selected for pQCT evaluation in this study did not allow evaluation of the cortical bone compartment . Future studies that utilize the pQCT technique need to incorporate multiple measurement sites to better assess total , cortical , and trabecular bone Childhood and adolescence is the period of most rapid skeletal growth in an individual 's lifetime . A greater peak bone mass achieved in the first 2 - 3 decades of life , may protect against the risk of osteoporotic fracture in later life . The aim of this r and omized , controlled study was to assess in pre-pubertal boys and girls ( aged 8 - 10 years ) the effect of 18 months of a calcium enriched , cocoa flavoured product on bone density , bone growth and bone size in New Zeal and children . One hundred and fifty four pre-pubertal boys and girls ( aged 8 - 10 years ) were r and omized to receive a high calcium dairy drink or a control drink reconstituted with water for 18 months . They were assessed at baseline and then every 6 months for the first 18 months , while they were having the supplement ; they were then followed up 12 months after supplementation had finished . Bone mineral density and bone mineral content were assessed at the total body , hip and spine . Indicators of bone size ( vertebral width and height ) were also measured at the spine . Anthropometric data was collected , medical history question naires were administered ( including the Tanner or pubertal stage question naire ) , dietary calcium intake was assessed with a calcium food frequency question naire and calcium supplement compliance was determined . There was no significant difference between the 2 groups for bone mineral density or bone mineral content at any time point . There was no difference in vertebral height or width at any stage of the study , indicating no additional influence on bone size at the lumbar vertebrae . There were no significant differences between height , weight , lean mass or fat mass at any time point . Both groups had higher habitual calcium intakes than recommended for this age group going into the study and throughout the study . In this 2(1/2 ) year study ( 18 months supplementation , 1 year follow-up ) we did not observe a difference in bone mineral density in pre-pubertal children . This was probably due to their high habitual dietary calcium intake whereby minimal addition of calcium to the diet reached the threshold level where no further benefit was seen . There were no significant differences between the two groups in body composition . Growth and the mean height and weight remained between the 50th and 75th percentile for their age . We have shown calcium supplementation in children with high habitual dietary calcium intake appears not to have additional effects on bone mass . Calcium supplementation needs to be targeted in those children with low habitual dietary calcium intake Summary Background Bone mineral density ( BMD ) is largely genetically determined and this influence is most powerful in the period of rapid skeletal development in childhood and late adolescence but environmental factors such as exercise and dietary calcium intake may influence up to 20 % . Aims of the study The aims of the study were to examine healthy late adolescent females for the effects and benefits of a high calcium intake from dairy product foods on bone mineral density , body composition , lipids and biochemistry . The secondary aim is determine whether a high intake of dairy product foods in the diet is acceptable for this age group long term . Methods Ninety-one teenage girls who participated in a two-year r and omised controlled study on the effect of dairy food supplementation on dietary patterns , body composition and bone density in post-pubertal teenage girls were approached one year after the cessation of the study to determine the effects of the cessation of dairy supplements on bone mineral density , dietary habits , biochemical markers , body composition and blood lipids . Bone mineral density and bone mineral content were assessed at the hip , spine and total body . Anthropometric data were collected , and exercise , Tanner , dietary assessment , preference and compliance question naires were administered . Lipid profiles , hydroxyproline excretion and urinary calcium and sodium excretion measurements were performed . Results There were no significant differences between the 2 groups for height , weight , lean and fat mass . The supplemented group had significantly higher calcium , phosphorus and protein intake during the supplementation period ( p<0.001 ) . No differences were seen between the groups 12 months after supplementation finished . There were no significant differences in exercise level , preference or acceptability of dairy products or in the lipids and bone markers between baseline the end of supplementation and 1 year follow-up . There was a significant increase in trochanter ( 4.6 % ) , lumbar spine ( 1.5 % ) and femoral neck ( 4.8 % ) BMD ( p<0.05 ) in the high calcium group at the end of supplementation . There was an increase in bone mineral content at the trochanter ( p<0.05 ) and lumbar spine ; however the latter was not statistically significant , in the high calcium group at the end of supplementation . There was no difference in vertebral height or width at any stage of the study , indicating no influence on bone size . Conclusions In this 3 year study ( 2 years of supplementation , 1 year follow-up ) , teenage girls , aged 15–18 years , were able to significantly increase their BMD at the trochanter , femoral neck and lumbar spine when supplemented with dairy product foods to a mean calcium intake of 1160 mg/d . There was also an effect seen on the BMC particularly at the trochanter and to a lesser extent at the lumbar spine . The dietary calcium intake achieved did not adversely affect body weight , fat and lean mass or blood lipid profiles . Twelve months after the supplementation finished the girls had returned to their baseline diet , indicating self- selection of a high dairy product diet may be hard to achieve BACKGROUND We conducted a r and omized , placebo-controlled , double-blind trial to test the hypothesis that vitamin D(3 ) supplementation would prevent bone loss in calcium-replete , African American postmenopausal women . METHODS Two hundred eight healthy black postmenopausal women , 50 to 75 years of age , were assigned to receive either placebo or 20 microg/d ( 800 IU ) of vitamin D(3 ) . Calcium supplements were provided to ensure a total calcium intake of 1200 to 1500 mg/d . After 2 years , the vitamin D(3 ) dose was increased to 50 microg/d ( 2000 IU ) in the active group , and the study continued for an additional year . Bone mineral density ( BMD ) was measured every 6 months . Markers of bone turnover , vitamin D metabolites , and parathyroid hormone ( PTH ) levels were measured in serum . RESULTS There were no significant differences in BMD between the active and control groups throughout the study . There was also no relationship between serum 25-hydroxyvitamin D levels attained and rates of bone loss . There was an increase in BMD of the total body , hip , and radius at 1 year in both groups . Over the 3 years , BMD declined at these sites by 0.26 % to 0.55 % per year . The BMD of the lumbar spine increased slightly in the placebo and active groups . There were no persistent changes in serum PTH levels or the markers of bone turnover , although there was a transient decline in PTH in both groups at 3 months . No significant adverse events were attributed to vitamin D supplementation . CONCLUSIONS There was no observed effect of vitamin D(3 ) supplementation on bone loss or bone turnover markers in calcium-replete , postmenopausal African American women . Further studies are needed to determine if these findings are applicable to women of other ethnic groups A r and omized controlled trial was carried out to determine whether calcium supplementation and load-bearing exercise can increase or maintain bone mass in the elderly . Fifty Chinese women , aged 62–92 years , living in a hostel for the elderly in Hong Kong were r and omized to enter one of four treatment groups : ( I ) calcium supplementation of 800 mg ( as calcium lactate gluconate ) daily ; ( II ) load-bearing exercise four times a week plus a daily placebo tablet ; ( III ) calcium supplementation daily and load-bearing exercise four times a week ; ( IV ) a placebo tablet daily . The interventions went on for 10 months . The bone mineral density ( BMD ) was measured at three sites in the hip ( femoral neck , Ward 's triangle and intertrochanteric area ) and the L2–4 level of the spine . The percentage change in BMD in 10 months was used as the main outcome measurement . The parathyroid hormone level and indices of bone metabolism were also measured before and after 10 months of intervention . The BMD at Ward 's triangle and the intertrochanteric area increased significantly in subjects on calcium supplement ( p<0.05 ) , but there was no significant change at the spine and femoral neck . Exercise had no effect on bone loss at any site . However , the results of two-way analysis of variance showed a significant joint effect of calcium supplements and exercise  at the femoral neck ( p<0.05 ) , but not at the other sites . The parathyroid hormone levels fell significantly in subjects on calcium supplements (p<0.01).Calcium supplement in the form of calcium lactate gluconate was adequately absorbed in elderly Chinese women with a calcium intake of less than 300 mg per day . It was effective in reducing bone loss at the hip , and there may be interaction effects with exercise in maintaining bone density Background Limited information is available on ways to influence osteoporosis risk in premenopausal women . This study tested four hypotheses regarding the effects of individualized bone density ( BMD ) feedback and different educational interventions on osteoporosis preventive behavior and BMD in pre-menopausal women , namely : that women are more likely to change calcium intake and physical activity if their BMD is low ; that group education will be more efficacious at changing behavior than an information leaflet ; that BMD feedback and group education have independent effects on behavior and BMD ; and , that women who improve their physical activity or calcium intake will have a change in bone mass over 2 years that is better than those who do not alter their behavior . Methods We performed a 2-year r and omized controlled trial of BMD feedback according to T-score and either an osteoporosis information leaflet or small group education in a population -based r and om sample of 470 healthy women aged 25–44 years ( response rate 64 % ) . Main outcome measures were dietary calcium intake , calcium supplement use , smoking behavior , physical activity , endurance fitness , lower limb strength and BMD . We used paired t-tests , one-way ANOVA and linear regression techniques for data analysis . Results Women who had feedback of low BMD had a greater increase in femoral neck BMD than those with normal BMD ( 1.6 % p.a . vs. 0.7 % p.a . , p = 0.0001 ) , but there was no difference in lumbar spine BMD change between these groups ( 0.1 % p.a . vs. 0.08 % p.a . , p = 0.9 ) . Both educational interventions had similar increases in femoral neck BMD ( Leaflet = + 1.0 % p.a . , Osteoporosis self-management course = + 1.3 % p.a . , p = 0.4 ) . Femoral neck BMD change was only significantly associated with starting calcium supplements ( 1.3 % p.a , 95%CI + 0.49 , + 2.17 ) and persistent self-reported change in physical activity levels ( 0.7 % p.a . , 95%CI + 0.22 , + 1.22 ) . Conclusion Individualized BMD feedback combined with a minimal educational intervention is effective at increasing hip but not spine bone density in premenopausal women . The changes in behavior through which this was mediated are potentially important in the prevention of other diseases , thus measuring BMD at a young age may have substantial public health benefits , particularly if these changes are sustained BACKGROUND Increased vitamin D intake may preserve or increase bone mineral density ( BMD ) in older persons . OBJECTIVE A 2-y double-blind study was undertaken to determine whether weekly administration of 10 000 units of vitamin D(2 ) maintained or increased BMD in younger postmenopausal women more efficiently than did calcium supplements alone . DESIGN One hundred eighty-seven women who were > or= 1 y postmenopausal were r and omly assigned to take either 1000 mg Ca/d after the evening meal or 1000 mg Ca/d plus 10 000 U vitamin D(2)/wk in a double-blind , placebo-controlled format . The BMD of the proximal forearm , lumbar spine , femoral neck , Ward 's triangle , and femoral trochanter was measured at 6-mo intervals by osteodensitometry . RESULTS During the 2-y period , there was no significant difference in the change in BMD at any site between the subjects taking calcium supplements and those taking calcium plus vitamin D(2 ) . Both groups significantly ( P < 0.005 ) gained BMD in Ward 's triangle and the femoral trochanter but significantly ( P < 0.005 ) lost bone in the proximal radius . There was no significant change in the lumbar spine or femoral neck BMD . CONCLUSION In younger postmenopausal women ( age : 56 y ) whose average baseline serum 25-hydroxyvitamin D concentration was well within the normal range , the addition of 10 000 U vitamin D(2)/wk to calcium supplementation at 1000 mg/d did not confer benefits on BMD beyond those achieved with calcium supplementation alone BACKGROUND Supplementation with calcium and vitamin D reduces bone loss and prevents fractures in elderly people , but it is not known whether any lasting benefit remains if the supplements are discontinued . OBJECTIVE The objective was to determine whether gains in bone mineral density ( BMD ) induced by calcium and vitamin D supplementation persist after supplement withdrawal . DESIGN Two-hundred ninety-five healthy , elderly men and women ( aged > /=68 y ) who had completed a 3-y r and omized , placebo-controlled trial of calcium and vitamin D supplementation were followed for an additional 2 y during which no study supplements were given .  BMD was measured by dual-energy X-ray absorptiometry , and biochemical variables related to calcium metabolism and bone turnover were measured . RESULTS In the 128 men , supplement-induced increases in spinal and femoral neck BMD were lost within 2 y of supplement discontinuation , but small benefits in total-body BMD remained . In the 167 women , there were no lasting benefits in total-body BMD or at any bone site . Consistent with the observations on BMD , the bone turnover rates in both men and women ( as measured by serum osteocalcin concentrations ) returned to their original higher concentrations within the same 2-y period . CONCLUSION Discontinued calcium and vitamin D supplementation has limited cumulative effect on bone mass in men and women aged > /=68 A 14-y follow-up of 581 children who took part in a r and omized controlled trial of the effect of a milk supplement on growth of children was conducted to investigate the supplement 's effect on adult bone mineral content ( BMC ) and density ( BMD ) . BMC and BMD of the nondominant forearm were measured by single-photon absorptiometry in 371 subjects ( 64 % ) aged 20 - 23 y , at a proximal site ( shaft of radius and ulna ) and at a distal site near the wrist .  BMC s and BMDs tended to be higher in the intervention group ( NS ) . Cross-sectionally , BMD was positively associated with body weight ( P less than 0.01 ) in both sexes ; inversely associated with alcohol consumption ( P less than 0.05 ) , and positively with manual occupation ( NS ) in men ; positively associated with current intakes of calcium ( P less than 0.05 ) , vitamin D ( P less than 0.01 ) , and sports activity during adolescence ( P less than 0.01 ) , and inversely with parity ( NS ) in women . In multiple linear-regression analysis body weight and sports activity during adolescence were stronger determinants of female BMD than was diet Two related studies were conducted to assess the associations between markers of skeletal modeling and remodeling in healthy children . Members of monozygotic twin pairs , aged 6 - 14 , enrolled in a clinical trial of calcium supplementation  , were studied at the end of the period of supplementation and for 3 years thereafter . Supplemented children had significantly higher rates of gain in bone mineral density ( BMD ) ( + 3 % on average ) during the period of supplementation accompanied by significantly lower concentrations of serum osteocalcin ( OC , -15 % ) . During postsupplement follow-up , both differences in BMD and OC disappeared . Black females , age matched to the baseline ages of the white children , had significantly lower serum concentrations of both OC and tartrate-resistant acid phosphatase ( TRAP ) at all ages and higher BMDs . When stratified on serum TRAP concentrations , regardless of race , children with lower concentrations had significantly higher BMDs , and no racial differences were apparent . In regression models accounting for 70 - 80 % of the variability in BMD in children , body size and TRAP , but not race , remained significantly associated with BMD . The skeletal advantages seen with calcium supplementation and black race appear to be associated with reduced rates of skeletal turnover . Given that markers of turnover during growth reflect both skeletal modeling and remodeling , and there is no apparent advantage to reduced skeletal modeling , it seems probable that reduced remodeling is the factor that accounts for the increases in bone mass The aim of the current study was to examine whether calcium supplementation could prevent bone loss in postmenopausal women or more favourable outcomes could be obtained via the consumption of dairy products fortified with calcium and vitamin D3 . For this purpose changes in bone mineral density ( BMD ) at different skeletal sites , assessed by dual-energy X-ray absorptiometry , as well as in quantitative ultrasound ( QUS ) parameters of the calcaneus over 12 months were estimated . A population of 101 postmenopausal women ( 55 - 65 years old ) was r and omized into a dairy group ( DG : n 39 ) , receiving approximately 1200 mg calcium/d and 7.5 microg vitamin D3/d through fortified dairy products ; a calcium-supplemented group ( CaG : n 26 ) provided with a calcium supplement of 600 mg/d ; and a control group ( CG : n 36 ) . Over the intervention period the DG was found to have more favourable changes in pelvis ( P=0.040 ) , total spine ( P<0.001 ) and total body BMD ( P<0.001 ) than the other groups . A significant increase was also observed for DG in lumbar spine BMD ( 2.0 % ; 95 % CI 0.5 , 3.5 ) although it did not differentiate significantly compared to the other groups . No significant differences were observed with respect to the changes in QUS parameters . The current study revealed that recommended intakes of vitamin D3 and calcium via fortified dairy products for 12 months can induce favourable changes in pelvis , total spine and total body BMD in postmenopausal women but not in QUS parameters . No such favourable changes were observed via supplementation of calcium alone BACKGROUND Our r and omized , placebo-controlled supplementation study of 160 rural Gambian children aged 8.3 - 11.9 y showed that an increase in calcium intake of 714 mg/d for 12 mo result ed in a 5 % increase in forearm bone mineral acquisition and a 22 % decrease in plasma osteocalcin concentration , a bone formation marker , but had no effect on height or bone dimensions . OBJECTIVE We investigated whether these results were sustained after supplement withdrawal . DESIGN All participants were followed up 12 ( FU1 ) and 24 ( FU2 ) mo after supplementation ended . Bone mineral content ( BMC ) , bone mineral density ( BMD ) , and BMC adjusted for bone width , body weight , and height ( size-adjusted BMC ) were measured at the midshaft and distal radius . Plasma osteocalcin concentration was measured at FU1 . RESULTS At follow-up , the calcium group had greater bone mineral status than did the placebo group at the midshaft radius ( mean difference + /- SE ) , FU1 : BMC ( 4.7 + /- 1.6 % ; P = 0.004 ) , BMD ( 5.1 + /- 1.1 % ; P < /= 0.0001 ) , size-adjusted BMC ( 5.0 + /- 1.1 % ; P < /= 0.0001 ) ; FU2 : BMC ( 3.8 + /- 1.6 % ; P = 0.02 ) , BMD ( 2.7 + /- 1.3 % ; P = 0.04 ) , size-adjusted BMC ( 2.5 + /- 1.3 % ; P = 0.06 ) . Similar differentials were observed at the distal radius but were not significant . No significant differences in plasma osteocalcin concentrations ( FU1 : -0.5 + /- 6.5 % ; P = 0.9 ) were observed between groups . CONCLUSION Although some of the effects of calcium supplementation were still evident at follow-up , further studies are required to determine whether short-term increases in calcium intake have lasting benefits for Gambian children Previous research suggests that physical activity may have a beneficial effect on  bone mineral density ( BMD ) in women . This relationship was explored in a 2-year , r and omized , intervention trial investigating the efficacy of exercise and calcium supplementation on increasing peak bone mass in young women . One hundred and twenty-seven subjects ( ages of 20 - 35 years ) were r and omly assigned either to an exercise program that contained both aerobics and weight training components or to a stretching program . Calcium supplementation ( up to 1500 mg/day including dietary intake ) or placebo was given in a double-blinded design to all subjects . Spinal trabecular BMD was determined using quantitative computed tomography ( QCT ) . Spinal integral , femoral neck , and trochanteric BMD were measured by dual X-ray absorptiometry ( DXA ) and calcaneal BMD by single photon absorptiometry ( SPA ) . Fitness variables included maximal aerobic capacity ( VO2max ) , and isokinetic muscle performance of the trunk and thigh . Measurements were made at baseline , 1 year , and 2 years . Sixty-three subjects ( 32 exercise , 31 stretching ) completed the study , and all the measured bone parameters indicated a positive influence of the exercise intervention . There were significant positive differences in BMD between the exercise and stretching groups for spinal trabecular ( 2.5 % ) , femoral neck ( 2.4 % ) , femoral trochanteric ( 2.3 % ) , and calcaneal ( 6.4 % ) measurements . The exercise group demonstrated a significant gain in BMD for spinal integral ( 1.3 + /- 2.8 % , p < 0.02 ) , femoral trochanteric ( 2.6 + /- 6.1 % , p < 0.05 ) , and calcaneal ( 5.6 + /- 5.1 , p < 0.01 ) measurements . In contrast to exercise , the calcium intervention had no positive effect on any of the bone parameters . In regard to fitness parameters , the exercise group completed the study with significant gains in VO2max and isokinetic ( peak torque ) values for the knee flexion and extension and trunk extension . This study indicates that over a 2-year period , a combined regimen of aerobics and weight training has beneficial effects on BMD and fitness parameters in young women . However , the addition of daily calcium supplementation does not add significant benefit to the intervention We previously reported that calcium intake enhanced the leg bone response to physical activity of preschool children in a 12-month r and omized trial of calcium supplementation and physical activity . To determine whether the intervention-induced changes in leg bone mineral content and size were maintained through the subsequent 12-month follow-up period , total body bone measurements by DXA and 20 % distal tibia pQCT bone measurements were obtained at 24 months ( 12 months post-intervention ) . Children also were measured for height and weight , and accelerometer readings were obtained in a subset of children at 18 and 24 months ( 6 and 12 months post-intervention ) . Regression analyses were performed controlling for covariates and indicated that increases from 12 to 24 months were greater in the gross motor ( GM ) activity group ( bone loading , large muscle exercises ) vs. fine motor ( FM ) activity group ( arts and crafts program ) for arm bone area ( BA ) ( P < 0.01 ) , total body ( P=0.04 ) and arm ( P < 0.01 ) bone mineral content ( BMC ) . There were no differences in BA or BMC changes from 12 to 24 months by calcium supplementation . Differences in tibia periosteal circumference by pQCT persisted at 24 months ( GM 51.4 + /- 0.4 mm vs. FM 50.2 + /- 0.4 mm , P=0.03 ) with a trend for greater endosteal circumferences in the children in the GM vs. FM groups at both 12 and 24 months ( both , P=0.08 ) . There were no significant differences in cortical area or thickness by activity or supplement group at 24 months . Children in the GM group had greater accelerometer counts/day ( P=0.04 ) and more time in vigorous activity ( P=0.05 ) at 18 months compared to FM group . No differences in accelerometer readings were noted at 24 months . In conclusion , we found higher activity levels in children r and omized to gross motor vs. fine motor activities 6 months after the intervention program ceased . Whether the greater periosteal circumference that was observed 12 months post-intervention was a persistent biological bone effect or due to persistently higher activity levels is not known High calcium intake during childhood has been suggested to increase bone mass accrual , potentially result ing in a greater peak bone mass . Whether the effects of calcium supplementation on bone mass accrual vary from one skeletal region to another , and to what extent the level of spontaneous calcium intake may affect the magnitude of the response has , however , not yet been clearly established . In a double-blind , placebo-controlled study , 149 healthy prepubertal girls aged 7.9+/-0.1 yr ( mean+/-SEM ) were either allocated two food products containing 850 mg of calcium ( Ca-suppl . ) or not ( placebo ) on a daily basis for 1 yr . Areal bone mineral density ( BMD ) , bone mineral content ( BMC ) , and bone size were determined at six sites by dual-energy x-ray absorptiometry . The difference in BMD gain between calcium-supplemented ( Ca-suppl . ) and placebo was greater at radial ( metaphysis and diaphysis ) and femoral ( neck , trochanter , and diaphyses ) sites ( 7 - 12 mg/cm2 per yr ) than in the lumbar spine ( 2 mg/cm2 per yr ) . The difference in BMD gains between Ca-suppl . and placebo was greatest in girls with a spontaneous calcium intake below the median of 880 mg/d . The increase in mean BMD of the 6 sites in the low-calcium consumers was accompanied by increased gains in mean BMC , bone size , and statural height . These results suggest a possible positive effect of calcium supplementation on skeletal growth at that age . In conclusion , calcium-enriched foods significantly increased bone mass accrual in prepubertal girls , with a preferential effect in the appendicular skeleton , and greater benefit at lower spontaneous calcium intake BACKGROUND Specific physical loading leads to enhanced bone development during childhood . A general physical activity program mimicking a real-life situation was successful at increasing general physical health in children . Yet , it is not clear whether it can equally increase bone mineral mass . We performed a cluster-r and omized controlled trial in children of both gender and different pubertal stages to determine whether a school-based physical activity ( PA ) program during one school-year influences bone mineral content ( BMC ) and density ( BMD ) , irrespective of gender . METHODS Twenty-eight 1st and 5th grade ( 6 - 7 and 11 - 12 year-old ) classes were cluster r and omized to an intervention ( INT , 16 classes , n=297 ) and control ( CON ; 12 classes , n=205 ) group . The intervention consisted of a multi-component PA intervention including daily physical education with at least 10 min of jumping or strength training exercises of various intensities . Measurements included anthropometry , and BMC and BMD of total body , femoral neck , total hip and lumbar spine using dual-energy X-ray absorptiometry ( DXA ) . PA was assessed by  accelerometers and Tanner stages by question naires . Analyses were performed by a regression model adjusted for gender , baseline height and weight , baseline PA , post-intervention pubertal stage , baseline BMC , and cluster . RESULTS 275 ( 72 % ) of 380 children who initially agreed to have DXA measurements had also post-intervention DXA and PA data . Mean age of prepubertal and pubertal children at baseline was 8.7±2.1 and 11.1±0.6 years , respectively . Compared to CON , children in INT showed statistically significant increases in BMC of total body , femoral neck , and lumbar spine by 5.5 % , 5.4 % and 4.7 % ( all p<0.05 ) , respectively , and BMD of total body and lumbar spine by 8.4 % and 7.3 % ( both p<0.01 ) , respectively . There was no gender * group , but a pubertal stage * group interaction consistently favoring prepubertal children . CONCLUSION A general school-based PA intervention can increase bone health in elementary school children of both genders , particularly before puberty 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 BACKGROUND High calcium intakes during adolescence may increase bone acquisition . The magnitude of the effect of dietary calcium supplementation and the timing of its administration to achieve significant effects on bone health are still incompletely defined . OBJECTIVE The objective of this study was to assess the effect of calcium supplementation on bone mass accretion in postmenarcheal adolescent girls with low calcium intakes . DESIGN A double-blind , placebo-controlled calcium supplementation study was implemented . One hundred girls with a mean ( + /- SD ) age of 14 + /- 0.5 y with habitual calcium intakes < 800 mg/d completed a 12-mo protocol . The treatment group received a daily supplement containing 1000 mg elemental calcium .  Bone mineral density ( BMD ) and bone mineral content ( BMC ) of the total body , lumbar spine , and femoral neck were determined at inclusion , 6 mo , and 12 mo . Also measured were serum concentrations of biochemical markers of bone turnover ( osteocalcin and deoxypyridinoline ) , parathyroid hormone , and vitamin D. RESULTS The calcium-supplemented group had greater accretion of total-body BMD and lumbar spine BMD but not BMC than did the control group . Calcium supplementation appeared selectively beneficial for girls who were 2 y postmenarcheal . Calcium supplementation significantly decreased bone turnover and decreased serum parathyroid hormone concentrations . CONCLUSION Calcium supplementation of postmenarcheal girls with low calcium intakes enhances bone mineral acquisition , especially in girls > 2 y past the onset of menarche The aim of this study was to determine whether early changes in bone markers could predict long-term response in bone mineral density ( BMD ) after calcium ( 500 mg ) and vitamin D ( 400 IU ) supplementation twice daily in ambulatory elderly women with vitamin D insufficiency ( 25-hydroxyvitamin D , < 12 ng/ml ) . One hundred and ninety-two women ( mean age , 75 + /- 7 yr ) were r and omized to receive either the supplementation ( n = 95 ) or a placebo ( n = 97 ) in a double-blind , controlled clinical trial for 1 yr . In comparison with the placebo group , supplementation significantly increased BMD , normalized 25-hydroxyvitamin D and significantly decreased intact PTH and bone remodeling markers . The initial values of telopeptide cross-links were correlated with improvement in total body BMD [ urinary N-telopeptides ( NTX ) , r = 0.38 ; C-telopeptides ( CTX ) , r = 0.32 ; serum CTX , r = 0.28 ] , and the 3-month changes in the same markers were correlated with improvement in total body ( urinary N-telopeptides , r = -0.29 ; serum CTX , r = -0.26 ) and vertebral BMD ( CTX , r = -0.26 ; all P < 0.05 ) . We concluded that short-term changes in bone resorption markers can predict long-term variations in BMD in elderly women with vitamin D insufficiency receiving calcium  and vitamin D supplementation To evaluate the correlation between dietary calcium intake and mineralization of the immature skeleton 55 children and adolescents aged 5 - 14 years ( mean , 9.5 years ) with a positive radioallergosorbent test ( RAST ) for serum antibodies to cow 's milk protein were evaluated .  Bone mineral density ( BMD ) in the lumbar spine and proximal femurs were measured by dual energy X-ray absorptiometry . BMD at each site for each subject was converted to an age-adjusted Z score based on our own series of 95 normal pediatric controls .  Calcium intake was determined using a detailed food frequency question naire administered by a nutritionist during a 30 - 40-min interview . Dietary adjustments to the condition varied and result ed in a wide range of calcium intakes . Calcium supplements were taken by 22 % of the subjects and were included in the determination of daily calcium intake . The group of 55 subjects was divided into quartiles based on calcium intake ( mean + /- S.E mg calcium/day ) : Group 1 , 409 + /- 21 , Group 2 , 663 + /- 16 , Group 3 , 950 + /- 32 , Group 4 , 1437 + /- 124 . Bone density Z scores in the proximal femur serially increased across the calcium intake groups ( mean + /- S.E. ) : Group 1 , -0.16 + /- 0.31 ; Group 2 , 0.05 + /- 0.33 ; Group 3 , 0.44 + /- 0.24 ; Group 4 , 0.79 + /- 0.41 ( P = 0.03 ) . A similar pattern was found with lumbar spine BMD Z scores : Group 1 , -0.16 + /- 0.27 ; Group 2 , 0.10 + /- 0.21 ; Group 3 , 0.18 + /- 0.20 ; Group 4 , 0.30 + /- 0.25 ( P = 0.05 ) . These data add further to the evidence that dietary calcium intake is important for optimal mineralization of the growing skeleton
There was no effect of calcium supplementation  on femoral neck or lumbar spine BMD .
There was no evidence of effect modification by baseline calcium intake , sex , ethnicity , physical activity or pubertal stage .
While there is a small effect of calcium supplementation in the upper limb , the increase in BMD which results is unlikely to result in a clinical ly significant decrease in fracture risk .
The results do not support the use of calcium supplementation  in healthy children as a public health intervention .
These results can not be extrapolated to children with medical conditions affecting bone metabolism
BACKGROUND Clinical trials have shown that  calcium supplementation in children can increase  bone mineral density ( BMD ) although this effect may not be maintained .
There has been no quantitative systematic review of this intervention .
To determine the effectiveness of calcium supplementation for improving BMD  in children .
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To determine if any effect varies by sex , pubertal stage , ethnicity or level of physical activity , and if any effect persists after supplementation is ceased .