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 .
Calcium supplementation increases stature and bone mineral mass of 16- to 18-year-old boys.
The effect of calcium carbonate supplementation on bone growth and mineral accretion was studied in 143 boys aged 16 - 18 yr , r and omized to 1000 mg Ca/d or a matching placebo for 13 months .  Anthropometry and dual-energy x-ray absorptiometry of the whole body , lumbar spine , hip , and forearm were performed before , during , and after the intervention . The intervention result ed in greater bone mineral content ( BMC ) of the whole body ( + 1.3 % , P = 0.02 ) , lumbar spine ( + 2.5 % , P = 0.004 ) , and hip ( total + 2.3 % , P = 0.01 ; neck + 2.4 % , P = 0.02 ; intertrochanter + 2.7 % , P = 0.01 ) . This was associated with greater height ( + 0.4 % , P = 0.0004 , equivalent to 7 mm ) , lean mass ( + 1.3 % , P = 0.02 ) , and lumbar spine bone area ( + 1.5 % , P = 0.003 ) . The increases in BMC diminished after size adjustment , suggesting that the intervention effect was mediated through an effect on growth . The BMC response at the intertrochanter was greater in subjects with high physical activity ( + 4.4 % , P = 0.05 ) . There were no other significant interactions with physical activity , plasma testosterone , calcium intake , or tablet compliance . We conclude that calcium carbonate supplementation  of adolescent boys increased skeletal growth , result ing in greater stature and bone mineral acquisition . Follow-up studies will determine whether this reflects a change in the tempo of growth or an effect on skeletal size that persists into adulthood
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 .