Matkovic 2004.

Methods	STUDY DESIGN: randomised controlled trial LOCATION AND SETTING: Community (school), USA DURATION OF SUPPLEMENTATION: 7 years DURATION OF FOLLOW‐UP: 7 years QUALITY ASSESSMENT: High risk of bias RANDOMISED: States random but no description ALLOCATION CONCEALMENT: Not described or unclear BLINDING OF SUBJECT: Yes DESCRIPTION OF WITHDRAWALS/DROPOUTS: No TYPE OF ANALYSIS: Available Data COMPLIANCE: Assessed CONFOUNDERS MEASURED: physical activity; dietary calcium, protein, energy intake; 24 hour urinary sodium; skeletal age, urinary and fecal calcium, serum calcium, serum vitamin D.
Participants	N SCREENED: unknown N RANDOMISED: 354 N COMPLETED: 220 (4 year); 179 (7 years) M=0% F=100% ETHNICITY: white MEAN BASELINE AGE (yrs): 10.8 BASELINE AGE RANGE (yrs): unknown INCLUSION CRITERIA: white, normal physical and mental health, pubertal stage 2, calcium intake <1480 mg/day, female EXCLUSION CRITERIA: history of metabolic bone, kidney, liver or celiac disease; use of oral corticosteroids, hormones, diuretics or antiseizure medications,; other current systemic, chronic disease; and the presence of clinically significant abnormal laboratory data on screening BASELINE CALCIUM INTAKE (mg/day): 837 PUBERTAL STAGE: peripubertal (Tanner stage 2)
Interventions	1. 1000 mg/day calcium as calcium citrate malate 2. Placebo CO‐INTERVENTIONS: Nil
Outcomes	BONE MEASURES: SITES AREAL BONE MINERAL DENSITY: distal radius, radius at 33% of the radius length, total body. BONE AREA: distal radius, radius at 33% of the radius length, total body. METHOD OF MEASUREMENT: DXA FOLLOW‐UP ASSESSMENT POINTS(yrs): 0, 1, 2, 4.5, 8.5 OTHER OUTCOMES MEASURED: metacarpal cortical index at 4 and 7 years, weight, height, body composition, serum osteocalcin and PTH and urinary N‐telopeptides. BONE MEASURES INCLUDED IN ANALYSES: AREAL BONE MINERAL DENSITY: distal radius, radius at 33% of the radius length, total body. BONE AREA: distal radius, radius at 33% of the radius length, total body. SUB‐GROUPS IDENTIFIED: nil
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	B ‐ Unclear