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 .
Prevention of bone demineralization by calcium supplementation in precocious puberty during gonadotropin-releasing hormone agonist treatment.
We have previously demonstrated a negative impact on peak bone mass in girls with precocious puberty treated with GnRH agonist ( GnRHa ) .  Several studies have shown that a high calcium intake positively influences bone mass in prepubertal girls and leads to a higher peak bone mass . The aim of this study was to evaluate the effect of calcium supplementation in girls with precocious puberty during GnRHa treatment .  Forty girls affected by true central precocious puberty and treated with the GnRHa triptorelin were studied for 2 yr . After diagnosis , the patients were r and omly assigned to three groups : group A , treated only with GnRHa ; group B , treated for 12 months solely with GnRHa and then supplemented with calcium gluconolactate/carbonate ( 1 g calcium/day in two doses ) for 12 months ; and group C , treated from the beginning with combined GnRHa and calcium .  Bone mineral density ( BMD ) at the lumbar spine was measured by dual energy x-ray absorptiometry at the beginning of the study and after 12 and 24 months and was expressed as the calculated true volumetric density ( BMDv ) in milligrams per cm3 . Group A showed a decrease in absolute BMDv levels , in SD score for chronological age ( CA ) , and even more in SD score for bone age ( BA ) . Group B showed the same behavior during the first year , but this trend was reversed in the second year , when calcium supplementation was added to GnRHa treatment . Group C showed an increase in absolute BMDv levels and in SD score for CA and BA . BMDv variations ( expressed as absolute values , SD score for CA , and SD score for BA ) became statistically significant at 24 months between groups C and A ( P = 0.036 , P = 0.032 , and P = 0.025 , respectively ) . The behavior of the lumbar spine BMDv in the three groups is consistent with a positive effect of calcium supplementation during GnRHa treatment . In calcium-supplemented patients , the normal process of bone mass accretion at puberty is preserved despite GnRHa treatment . Therefore , the reduction in BMD during GnRHa treatment in girls with precocious puberty is at least completely reversible and preventable if calcium supplementation is associated from the beginning
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 .