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 .
YOUTH: decisions and challenges in designing an osteoporosis prevention intervention for teen girls.
BACKGROUND This paper describes decisions about the experimental design for the Youth , Osteoporosis , and Underst and ing Total Health Project ( YOUTH ) , a trial design ed to test the efficacy of a health plan-based lifestyle intervention for increasing bone mineral density among adolescent women 14 to 16 years of age . METHODS This r and omized controlled trial recruited adolescent women who were at higher risk for developing osteoporosis ( body mass index 16 - 23 ) from a large HMO in the Pacific Northwest . The intervention focused on improving diet ( high calcium foods , fruits , and vegetables ) and increasing physical activity ( high impact and spinal motion ) . The intervention included both group and individual activities . The primary endpoint in the study was total bone mineral density as measured by dual-energy X-ray absorptiometry ( DEXA ) . RESULTS Baseline data were collected on the trial cohort of 228 adolescent women and their families . This paper discusses how research ers met the following challenges in design ing and implementing the trial : determining appropriate dietary and exercise targets to affect bone mineral density in adolescents ; choosing suitable assessment s ; and developing an intervention well suited for implementation in a non-school ( health plan ) setting . We also discuss the rationale for the specific study population chosen ( females , younger adolescents ) . CONCLUSIONS The YOUTH project is one of very few preventive research interventions with adolescents conducted in a health plan setting . Many of the recruitment and intervention strategies used in this trial may be appropriate for adoption in other health plan-based prevention studies
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 .