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 increases in bone mineral density in children.
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
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 .