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 .
Randomized trial of physical activity and calcium supplementation on bone mineral content in 3- to 5-year-old children.
A meta- analysis of adult exercise studies and an infant activity trial show a possible interaction between physical activity and calcium intake on bone . This r and omized trial of activity and calcium supplementation was conducted in 239 children aged 3 - 5 years ( 178 completed ) . Children were r and omized to participate in either gross motor or fine motor activities for 30 minutes/day , 5 days per week for 12 months . Within each group , children received either calcium ( 1000 mg/day ) or placebo .  Total body and regional bone mineral content by DXA and 20 % distal tibia measurements by peripheral quantitative computed tomography ( pQCT ) were obtained at 0 and 12 months . Three-day diet records and 48-h accelerometer readings were obtained at 0 , 6 , and 12 months . Higher activity levels were observed in gross motor versus fine motor activity groups , and calcium intake was greater in calcium versus placebo ( 1354 + /- 301 vs. 940 + /- 258 mg/day , p < 0.001 ) . Main effects of activity and calcium group were not significant for total body bone mineral content or leg bone mineral content by DXA . However , the difference in leg bone mineral content gain between gross motor and fine motor was more pronounced in children receiving calcium versus placebo ( interaction , p = 0.05 ) . Children in the gross motor group had greater tibia periosteal and endosteal circumferences by pQCT compared with children in the fine motor group at study completion ( p < 0.05 ) . There was a significant interaction ( both p < or = 0.02 ) between supplement and activity groups in both cortical thickness and cortical area : among children receiving placebo , thickness and area were smaller with gross motor activity compared with fine motor activity , but among children receiving calcium , thickness and area were larger with gross motor activity . These findings indicate that calcium intake modifies the bone response to activity in young children
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 .