Calcium supplementation and bone mineral density in females from childhood to young adulthood: a randomized controlled trial. Appendicular bone mass in children with a high prevalence of low dietary calcium intakes. Effect of habitual dietary calcium intake on calcium supplementation in 12-14-y-old girls. Calcium-enriched foods and bone mass growth in prepubertal girls: a randomized, double-blind, placebo-controlled trial. 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. Calcium supplementation provides an extended window of opportunity for bone mass accretion after menarche. 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] Calcium intake influences the association of protein intake with rates of bone loss in elderly men and women. Dietary calcium intake protects women consuming oral contraceptives from spine and hip bone loss. Dairy intakes affect bone density in the elderly. Effect of calcium supplementation on bone mineral accretion in gambian children accustomed to a low-calcium diet. Implementing an intervention to improve bone mineral density in survivors of childhood acute lymphoblastic leukemia: BONEII, a prospective placebo-controlled double-blind randomized interventional longitudinal study design. Effect of milk and calcium supplementation on bone density and bone turnover in pregnant Chinese women: a randomized controlled trail Double-blind, controlled calcium supplementation and bone mineral accretion in children accustomed to a low-calcium diet. Factors affecting bone density in young adults. Calcium supplementation and increases in bone mineral density in children. Bone minerals changes in obese women during a moderate weight loss with and without calcium supplementation.
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 We have previously documented evidence of dietary calcium deficiency in black children living in a rural community in the eastern part of South Africa . The present study determined the bone mass of the distal one-third of the radius in a r and om sample of children living in the same community and compared their bone mass measurements with those of black children living in a similar rural community but without evidence of dietary calcium deficiency . Further , factors ( weight , height , serum corrected total calcium , phosphorus , and alkaline phosphatase [ ALP ] ) that might influence appendicular bone mass were assessed and correlated with the bone mass measurements . A r and om sample of 306 boys and 345 girls between the ages of 1 and 20 years were included in the study .  Hypocalcemia was found in 6.5 % of the boys and 5 % of the girls , while elevated ALP values were recorded in 20 and 26 % of the boys and girls , respectively . After adjusting for differences in age , weight , and height , bone mineral density ( BMD ) and bone mineral apparent density ( BMAD ) were significantly lower and bone width ( BW ) greater in study than control children . In a stepwise regression analysis , weight and /or height accounted for the majority of the observed variance in BMC , BW , and BMD ; however , a significant effect of serum calcium ( positively ) and ALP ( negatively ) on BMC and BMD was also found . In boys , but not girls , serum ALP also had a positive effect on BW.BMAD was negatively correlated to ALP and positively correlated to serum calcium in both boys and girls . Those children with hypocalcemia or elevated ALP levels had significantly lower BMC , BMD , and BMAD and a trend toward greater BW than children with normal biochemistry . The findings suggest that low dietary calcium intake may have a detrimental effect on appendicular bone density in rural black children . Whether or not these effects are disadvantageous in the long-term is not known BACKGROUND There is no agreement on how much calcium young girls need for optimal bone mineralization . OBJECTIVE We evaluated whether the effect of calcium supplementation on whole-body bone mineral accretion depends on habitual calcium intake . DESIGN This was a r and omized , double-blind , placebo-controlled , 1-y calcium intervention study of girls aged 12 - 14 y selected from a larger group according to habitual calcium intake : subgroup A ( n = 60 ) habitually consumed 1000 - 1307 mg/d ( 40th-60th percentile ) , and subgroup B ( n = 53 ) habitually consumed < 713 mg/d ( < 20th percentile ) . The girls from each subgroup were r and omly assigned to receive either 500 mg Ca/d or placebo .  Whole-body bone mineral content ( BMC ) , bone area ( BA ) , bone mineral density ( BMD ) , and BMC adjusted for BA , height , and weight ( size-adjusted BMC ) were measured at baseline and after 1 y. RESULTS There was no significant effect modification of baseline habitual calcium intake on the relation between calcium supplementation and height , weight , BMC , size-adjusted BMC , BA , BMD , or alkaline phosphatase .  Calcium supplementation had an effect on BMD ( 0.8 % ; P = 0.049 ) and tended to show signs of an effect on size-adjusted BMC ( 0.5 % ; P = 0.08 ) . CONCLUSION A modest effect of calcium supplementation on BMD was shown . However , the effect was independent of habitual calcium intake 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 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 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 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 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 CONTEXT It is estimated that 80 % of all women have used oral contraceptives ( OCP ) , but OCP use may prevent attainment of maximal peak bone mass in young women and thus increase the risk of osteoporosis later in life . OBJECTIVE This study examined whether increased calcium intake could reduce the detrimental effects of OCP use on bone mass in young women . DESIGN The study design was a 1-yr intervention . SETTING The study was performed in a general community setting . SUBJECTS One hundred fifty-four young ( 18 - 30 yr old ) healthy women with a dietary calcium intake of less than 800 mg/d began the study , and 135 completed the trial . INTERVENTION Subjects were r and omly assigned to one of three diet intervention groups : 1 ) control , continuous established ( < 800 mg/d ) dietary calcium intake ; 2 ) medium dairy , increase calcium intake to approximately 1000 - 1100 mg/d ; and 3 ) high dairy , increase calcium intake to approximately 1200 - 1300 mg/d . R and omization was stratified by OCP use . MAIN OUTCOME MEASURES The main outcome measures were total body bone mineral density ( BMD ) and content ( BMC ) ; total hip BMD , BMC , and bone area ; and spine BMD , BMC , and bone area . RESULTS Dairy product intervention positively impacted the percentage change in total hip BMD and BMC . In addition , dairy product intake prevented a negative percentage change in total hip and spine BMD in OCP users . CONCLUSION Dairy product intake , at levels necessary to achieve the recommended intakes of calcium , protected the total hip BMD and spine BMD from loss observed in young healthy women with low calcium intakes who were using OCP BACKGROUND Race and sex differences in the effect of diet on bone mineral density ( BMD ) at the hip in the elderly are unknown . OBJECTIVES This study related cross-sectional nutrient and dairy product consumption to hip BMD in white and black men and women aged > 60 y and evaluated the influence of nutrient and dairy product consumption on changes in BMD in a white cohort participating in a calcium , vitamin D , or placebo trial . DESIGN The Health Habits and History Question naire was used in 289 white women and 116 white men who participated in the trial and in 265 black women and 75 black men to predict total hip and femoral neck BMD or  changes in BMD . RESULTS Blacks had higher calcium intakes than did whites ( 700 and 654 mg/d , respectively ; P = 0.0094 ) , and men had higher calcium intakes than did women ( 735 and 655 mg/d , respectively ; P = 0.0007 ) . For men , the correlation between total hip BMD and dairy calcium intake after adjustment for age , race , and weight was 0.23 ( P < 0.005 ) ; this relation was not significant in women ( r = 0.02 , P = 0.12 ) . Similar results were found for femoral neck BMD . In the longitudinal study , calcium supplementation reduced bone loss from the total hip and femoral neck in those who consumed < 1.5 servings of dairy products/d and were < 72 y old . CONCLUSIONS Cross-sectional results indicated that higher dairy product consumption is associated with greater hip BMD in men , but not in women . Calcium supplementation protected both men and women from bone loss in the longitudinal study of whites 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 The BONEII study is a large two-phase study . The baseline study ( Study 1 ) aims to estimate the prevalence of diminished bone mineral density ( BMD ) in patients treated for childhood acute lymphoblastic leukemia ( ALL ) and identify risk factors for BMD deficits . The interventional phase ( Study 2 ) of BONEII has a placebo-controlled double-blind r and omized longitudinal design to evaluate the effects of nutritional counseling and calcium and vitamin D supplementation on changes in BMD and serum and urine markers of bone metabolism . The extensive information being collected through this large study will serve as a repository of relational data about BMD and bone turnover and will support further investigations to assess the association of calcium metabolism , bone turnover , nutritional intake , lifestyle factors ( such as exercise and the use of alcohol and tobacco ) , and the specific agents used in ALL therapy in this rapidly increasing population of childhood cancer survivors Objective Calcium dem and is increased during pregnancy . However , few r and omized controlled trials examined the effects of calcium supplementation on bone mass during pregnancy . This study determined effects of calcium and milk supplementation on maternal bone mineral density ( BMD ) and bone turnover in pregnant Chinese women with habitual low calcium intake . Methods In this r and omized controlled trial , 36 Chinese pregnant women ( 24–31 years , 18 gestational weeks ) were r and omly assigned to the following three arms ( 12 each ) : I , usual diet ; II , “ I ” + 45 g milk powder ( containing 350 mg calcium ) ; or III , “ II ” + 600 mg calcium/day from gestational age of 20 weeks to 6 weeks post-partum ( PP ) . BMD was measured post-treatment using dual-energy X-ray absorptiometry . Dietary intakes , 24-h urinary calcium , bone resorption ( urinary hydroxyproline ) and formation ( serum osteocalcin ) biomarkers were examined at the gestational age of 20 and 34 weeks , and 6 weeks PP . Results A dose-dependent relationship was observed between calcium intake and BMDs . The BMD values were significantly higher in subjects with calcium and milk supplementation  than those in the controls at the whole body and spine ( p < 0.05 ) but not at the hip sites . We found significant decreases in changes of urinary hydroxyproline , and significant increases in serum osteocalcin during the intervention period in the calcium/milk intervention groups than those in the control group ( all p < 0.05 ) . Conclusion Calcium/milk supplementation during pregnancy is associated with greater BMD at the spine and whole body and suppresses bone resorption in Chinese women with habitual low calcium intake A r and omized , double-blind , controlled calcium supplementation trial was conducted for 18 mo to determine its effects on bone acquisition and height increment in 162 7-y-old Chinese children ( 87 boys and 75 girls ) with habitually low calcium intakes ( 280 mg/d ) . Distal one-third radial bone mineral content ( BMC ) , area bone density ( BMC /bone width ) , and height were evaluated every 6 mo . Baseline dietary intakes , serum 25-hydroxycholecalciferol , and physical activity  were determined . The study group received 300 mg Ca/d as calcium carbonate ; control subjects received placebo tablets . After 18 mo the study group had significantly greater gains in BMC ( 16.5 % vs 13.97 % ; P = 0.02 ) and BMC /bone width ( 9.45 % vs 6.31 % ; P = 0.0008 ) than the control subjects . The findings confirm a positive effect of calcium intake on bone acquisition but no effect on height increment . Whether a higher bone mass attained at age 8 - 9 y would be maintained and beneficial to future peak bone mass requires longitudinal investigation . Further study is warranted to determine calcium requirements for Chinese children 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 BACKGROUND Increased dietary intake of calcium during childhood , usually as calcium in milk , is associated with increased bone mass in adulthood ; the increase in mass is important in modifying the later risk of fracture . Whether the increase is due to the calcium content of milk , however , is not certain . METHODS We conducted a three-year , double-blind , placebo-controlled trial of the effect of calcium supplementation ( 1000 mg of calcium citrate malate per day ) on bone mineral density in 70 pairs of identical twins ( mean [ + /- SD ] age , 10 + /- 2 years ; range , 6 to 14 ) . In each pair , one twin served as a control for the other ; 45 pairs completed the study .  Bone mineral density was measured by photon absorptiometry at two sites in the radius ( at base line , six months , and one , two , and three years ) and at three sites in the hip and in the spine ( at base line and three years ) . RESULTS The mean daily calcium intake of the twins given placebo was 908 mg , and that of the twins given calcium supplements was 1612 mg ( 894 mg from the diet and 718 mg from the supplement ) . Among the 22 twin pairs who were prepubertal throughout the study , the twins given supplements had significantly greater increases in bone mineral density at both radial sites ( mean difference in the increase in bone mineral density : midshaft radius , 5.1 percent [ 95 percent confidence interval , 1.5 to 8.7 percent ] ; distal radius , 3.8 percent [ 95 percent confidence interval , 1.4 to 6.2 percent ] ) and in the lumbar spine ( increase , 2.8 percent [ 95 percent confidence interval , 1.1 to 4.5 percent ] ) after three years ; the differences in the increases at two of three femoral sites approached significance ( Ward 's triangle in the femoral neck , 2.9 percent ; greater trochanter , 3.5 percent ) . Among the 23 pairs who went through puberty or were postpubertal , the twins given supplements received no benefit . CONCLUSIONS In prepubertal children whose average dietary intake of calcium approximated the recommended dietary allowance , calcium supplementation increased the rate of increase in bone mineral density . If the gain persists , peak bone density should be increased and the risk of fracture reduced A significant relationship between body weight ( BW ) and bone mass ( BM ) has been established previously . A diet-induced weight loss is accompanied by a significant decrease in bone mineral density ( BMD ) and total body bone mineral ( TBBM ) , but the underlying mechanisms are not clarified . Sixty-two obese women were included in the study .  Dual-energy X-ray absorptiometry ( DXA ) and measurements of a series of calcium-regulating hormones and biochemical markers of bone turnover were performed at baseline and after 1 month and 3 months on a low calorie diet . Thirty of the women were r and omized to a daily supplement of 1 g of calcium . After an additional 3 months without dietary prescriptions or calcium supplements , a subgroup of 48 subjects ( 24 from each group ) were scanned again using DXA . There was a significant decrease in TBBM after 1 month and 3 months . A similar pattern was observed in the bone mineral content ( BMC ) of the lumbar spine in the patients who did not receive a calcium supplement , whereas no changes occurred in the supplemented group . The initial calcium supplementation seemed to protect against bone loss in the lumbar spine but not in the TBBM . In the nonsupplemented group , a statistically significant inverse correlation was found between the calcium/creatinine ratio in the morning urine and the changes in BMC of the lumbar spine . Such a relationship was not seen in the calcium-supplemented group . In the nonsupplemented group , no significant biochemical changes were observed , whereas a significant decrease in serum parathyroid hormone ( PTH ) was seen in the calcium-supplemented group . This might explain some of the protective effects of calcium supplementation on trabecular bone mass . We conclude that a diet-induced weight loss is accompanied by a generalized bone loss , which probably is explained mainly by a reduced mechanical strain on the skeleton . This loss can be partly inhibited by a high calcium intake . Therefore , a calcium supplementation should be recommended during weight loss , even if the diet contains the officially recommended amounts of calcium
Calcium supplements  increased BMD by 0.7 - 1.8 % at all five skeletal sites at one , two , and over two and a half years , but the size of the increase in BMD at later time points was similar to the increase at one year .
Increasing calcium intake from dietary sources or by taking calcium supplements produces small non-progressive increases in BMD , which are unlikely to lead to a clinical ly significant reduction in risk of fracture
OBJECTIVE To determine whether increasing calcium intake from dietary sources affects  bone mineral density ( BMD ) and , if so , whether the effects are similar to those of calcium supplements .