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 .
Skeletal site selectivity in the effects of calcium supplementation on areal bone mineral density gain: a randomized, double-blind, placebo-controlled trial in prepubertal boys.
BACKGROUND Calcium supplementation during childhood and adolescence is considered an early means of preventing osteoporosis in adults . Prepuberty is an opportune time for detecting the benefits of calcium in girls . OBJECTIVE The objective was to assess whether calcium supplementation increases bone mass gain in prepubertal boys in a skeletal site-specific manner . METHODS In a 12-month double-blind , placebo-controlled trial with 1-yr follow-up , 235 healthy prepubertal boys aged 7.4 + /- 0.4 yr ( mean + /- sd ) were r and omized to receive two food products providing 850 mg/d calcium ( calcium supplement group , n = 116 ) or an isocaloric placebo ( n = 119 ) . Areal bone mineral density ( aBMD ) was determined by dual-energy x-ray absorptiometry at radius ( two sites ) , hip ( two sites ) , femoral diaphysis ( FDia ) , and L2-L4 vertebrae . RESULTS At 12 months , aBMD gain was greater at the FDia and at the mean of the five appendicular skeletal sites in the calcium supplement group in both intention-to-treat analysis [ 76 + /- 32 vs. 64 + /- 33 mg/cm(2).yr ; difference , 12.0 ( 95 % confidence interval , CI , 3.6 - 20.3 ) , P = 0.006 ; and 33 + /- 16 vs. 28 + /- 16 mg/cm(2).yr ; difference , 5.1 ( 95 % CI , 0.9 - 9.2 ) ; P = 0.018 , respectively ] and active treatment analysis [ 81 + /- 32 vs. 64 + /- 31 mg/cm(2).yr ; difference , 17.2 ( 95 % CI , 7.9 - 26.5 ) ; n = 174 , P < 0.001 ; and 35 + /- 16 vs. 28 + /- 14 mg/cm(2).yr ; difference , 7.5 ( 95 % CI , 2.9 - 12.2 ) ; P = 0.002 ] . There was no beneficial effect of calcium on lumbar spine . The calcium effect was still detectable by ANOVA repeated measures analysis at the FDia ( P = 0.004 ) and at the mean of the five appendicular skeletal sites ( P = 0.002 ) 1 yr after the end of intervention ( active treatment analysis ) . There was no change in bone size . CONCLUSION In prepubertal boys , calcium-enriched foods increased aBMD at several appendicular skeleton sites , but not at the lumbar spine , and this without any bone size change . This effect was maintained 1 yr after treatment discontinuation
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 .