Cameron 2004.

Methods	STUDY DESIGN: randomised controlled trial LOCATION AND SETTING: Community (Twin register), Australia DURATION OF SUPPLEMENTATION: 2 years DURATION OF FOLLOW‐UP: 2 years QUALITY ASSESSMENT: Moderate risk of bias RANDOMISED: States random but no description ALLOCATION CONCEALMENT: Not described or unclear BLINDING OF SUBJECT: Yes DESCRIPTION OF WITHDRAWALS/DROPOUTS: Yes TYPE OF ANALYSIS: Available Data COMPLIANCE: Assessed CONFOUNDERS MEASURED: spontaneous calcium intake, physical activity, medical history and medication use.
Participants	N SCREENED: unknown N RANDOMISED: 128 N COMPLETED: 104 (6 months); 48 (2 years) M=0% F=100% ETHNICITY: unknown MEAN BASELINE AGE (yrs): 10.3 BASELINE AGE RANGE (yrs): 8‐13 INCLUSION CRITERIA: premenarcheal female twins EXCLUSION CRITERIA: nil BASELINE CALCIUM INTAKE (mg/day): 716 PUBERTAL STAGE: prepubertal
Interventions	1. Calcium carbonate 1200 mg 2. Placebo CO‐INTERVENTIONS: Nil
Outcomes	BONE MEASURES: SITES AREAL BONE MINERAL DENSITY: total hip, femoral neck, total forearm and L2‐4 vertebrae. BONE MINERAL CONTENT: total body METHOD OF MEASUREMENT: DXA FOLLOW‐UP ASSESSMENT POINTS(yrs): 0, 0.5, 1, 1.5, 2 OTHER OUTCOMES MEASURED: weight, height, fat mass, lean mass BONE MEASURES INCLUDED IN ANALYSES: AREAL BONE MINERAL DENSITY: total hip, femoral neck, total forearm and L2‐4 vertebrae. BONE MINERAL CONTENT: total body SUB‐GROUPS IDENTIFIED: Menarche vs premenarche
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	B ‐ Unclear