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 .
Calcium supplementation and bone mineral density in females from childhood to young adulthood: a randomized controlled trial.
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
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 .
.
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 .