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 .
CAUSAL ANALYSIS OF EXERCISE AND CALCIUM INTAKE BEHAVIORS FOR OSTEOPOROSIS PREVENTION AMONG YOUNG WOMEN IN THAILAND
The goal of health education is to provide information to affect attitudes , beliefs , and intentions for behavior change . However , little is known about the effects of changes in knowledge on behaviors for osteoporosis prevention . Our objective is to develop and test theoretical models of the effects of knowledge , attitude , and self-efficacy on exercise and calcium intake among young women before and after an intervention program .  First , we hypothesized that knowledge would positively predict attitude , self-efficacy , calcium intake , and exercise .  Second , attitude would positively predict self-efficacy , calcium intake , and exercise .  Third , self-efficacy would positively predict calcium intake and exercise  . Fourth , attitude and self-efficacy would mediate the effect of knowledge on calcium intake and exercise . At the beginning and end of the study , participants in the control group and intervention group completed the  osteoporosis knowledge test , the osteoporosis health belief scale , the osteoporosis self-efficacy scale , a self-report for food records , and exercise .  The causal model was examined as a result of our study . After the intervention program ,  calcium intake and exercise  were predicted by knowledge when mediated by attitudes and self-efficacy . The final model accounted for 30 % and 45 % of the variance in calcium intake and exercise , respectively . We conclude that interventions to enhance young women 's  knowledge and self-efficacy may result in increased calcium intake and exercise
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 .