Reid 2010

Methods	Randomised controlled trial. The trial was conducted in New Zealand.
Participants	323 healthy men. Age: over 40 years.
Interventions	Intervention groups: group 1: 600 mg calcium a day or group 2: 1200 mg calcium a day as calcium citrate. Control group: placebo. Trial duration: 2 years.
Outcomes	Primary endpoint: change in the ratio of HDL to LDL cholesterol Secondary endpoints: changes in cholesterol fractions, triglycerides, blood pressure, and body composition
Notes	This study was supported by Mission Pharmacal
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Treatments were allocated randomly by using computer‐generated random numbers (Microsoft Excel 2003; Microsoft, Redmond, WA) within blocks of random sizes in multiples of 3."
Allocation concealment (selection bias)	Low risk	"Randomization was performed before the study began by the study statistician and was conveyed to a staff member who dispensed the study medication into numbered containers. This individual had no direct contact with other study staff nor with trial participants. Subjects were allocated a study number according to the sequence of their enrolment."
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Participants and study staff were blinded to treatment allocation throughout the study.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	"Blood pressure was measured by using a Dinamap automatic monitor (Johnson & Johnson, Tampa, FL)."
Incomplete outcome data (attrition bias) All outcomes	Low risk	"Complete follow‐up was achieved in 96% of the participants, and the proportions of those randomly assigned still receiving the trial medication at study end were as follows: 93% in the placebo group, 91% in the Ca600 group, and 86%in the Ca1200 group (P = 0.19 for between‐group comparisons)."
Selective reporting (reporting bias)	Low risk	All outcomes were reported.
Other bias	Low risk	There were small differences (in different directions) between intervention and placebo participants.