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 .
Jumping improves hip and lumbar spine bone mass in prepubescent children: a randomized controlled trial.
Physical activity during childhood is advocated as one strategy for enhancing peak bone mass ( bone mineral content [ BMC ] ) as a means to reduce osteoporosis-related fractures . Thus , we investigated the effects of high-intensity jumping on hip and lumbar spine bone mass in children . Eighty-nine prepubescent children between the ages of 5.9 and 9.8 years were r and omized into a  jumping  ( n = 25 boys and n = 20 girls ) or  control group  ( n = 26 boys and n = 18 girls ) . Both groups participated in the 7-month exercise intervention during the school day three times per week . The jumping group performed 100 , two-footed jumps off 61-cm boxes each session , while the control group performed nonimpact stretching exercises .  BMC ( g ) , bone area ( BA ; cm2 ) , and bone mineral density ( BMD ; g/cm2 ) of the left proximal femoral neck and lumbar spine ( L1-L4 ) were assessed by dual-energy X-ray absorptiometry ( DXA ; Hologic QDR/4500-A ) . Peak ground reaction forces were calculated across 100 , two-footed jumps from a 61-cm box . In addition , anthropometric characteristics ( height , weight , and body fat ) , physical activity , and dietary calcium intake were assessed . At baseline there were no differences between groups for anthropometric characteristics , dietary calcium intake , or bone variables . After 7 months , jumpers and controls had similar increases in height , weight , and body fat . Using repeated measures analysis of covariance ( ANCOVA ; covariates , initial age and bone values , and changes in height and weight ) for BMC , the primary outcome variable , jumpers had significantly greater 7-month changes at the femoral neck and lumbar spine than controls ( 4.5 % and 3.1 % , respectively ) . In repeated measures ANCOVA of secondary outcomes ( BMD and BA ) , BMD at the lumbar spine was significantly greater in jumpers than in controls ( 2.0 % ) and approached statistical significance at the femoral neck ( 1.4 % ; p = 0.085 ) . For BA , jumpers had significantly greater increases at the femoral neck area than controls ( 2.9 % ) but were not different at the spine . Our data indicate that jumping at ground reaction forces of eight times body weight is a safe , effective , and simple method of improving bone mass at the hip and spine in children . This program could be easily incorporated into physical education classes
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 .