Lappe 2007.

Methods	Randomised, double‐blind, placebo‐controlled trial using parallel group design (3 intervention groups)
Participants	Number of participants randomised: 1179 healthy postmenopausal white women, 55 years of age and older (mean 66.7) Inclusion criteria: age > 55 years, at least 4 years past last menses; in generally good health, living independently in the community, and weighing less than 300 pounds Exclusion criteria: a medical diagnosis of any chronic kidney disease, Paget's or other metabolic bone disease, and history of cancer except for superficial basal or squamous cell carcinoma of the skin and other malignancies treated curatively more than 10 years prior to entry into the trial
Interventions	Participants were randomly assigned to receive: Intervention group 1: vitamin D₃ (1000 IU) plus calcium (1400 to 1500 mg) daily (n = 446) Intervention group 2: vitamin D₃ placebo plus calcium (1400 to 1500 mg) daily (n = 445) Comparator group: placebo, consisting of both vitamin D₃ placebo and a brand‐specific calcium placebo daily (n = 288), for a 4‐year period.
Outcomes	Outcomes reported in abstract of publication Primary outcomes: fracture incidence. Secondary outcomes: cancer incidence.
Stated aim of study	Quote from the publication: "To determine the efficacy of calcium alone and calcium plus vitamin D in reducing incident cancer risk of all types."
Notes	"Compliance with trial medication was assessed at six months intervals by bottle weight. Mean adherence (defined as taking 80% of assigned doses) was 85.7% for the vitamin D component of the combined regimen and 74.4% for the calcium component." „None of the authors was affiliated in any way with an entity involved with the manufacture or marketing of vitamin D. RRR has served on scientific advisory boards for Lilly, P&G, Merck, Roche, and Amgen. RPH has served on scientific advisory boards for the International Dairy Foods Association and ConAgra and on the speaker bureau for Merck and P&G.“ Additional information on mortality was received through personal communication with Professor Joan M Lappe (21.11.2007).
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote from the publication: "The study statistician generated the randomization sequence with the use of a computer‐generated permuted blocks (n = 5) randomization scheme, and the study nurses enrolled the subjects and assigned them to groups." Comment: sequence generation was achieved using computer random number generation.
Allocation concealment (selection bias)	Low risk	Quote from the publication: "The study statistician generated the randomization sequence." Comment: allocation was controlled by a central and independent randomisation unit so that intervention allocations could not have been foreseen in advance of, or during, enrolment.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Comment: there was insufficient information to assess whether blinding was likely to introduce bias into the results.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Comment: there was insufficient information to assess whether blinding was likely to introduce bias into the results.
Incomplete outcome data (attrition bias)	High risk	Quote from the publication: "Of 1180 women enrolled, 1024 (86.8%) completed the 4 y of study. Most of the losses (n = 92) occurred within the first year." Comment: the numbers and reasons for dropouts and withdrawals in all intervention groups were not described.
Selective reporting (reporting bias)	Low risk	Comment: predefined, or clinically relevant and reasonably expected outcomes were reported.
For‐profit bias	High risk	Quote from the publication: "The calcium supplements were provided by Mission Pharmacal (San Antonio, TX) and GlaxoSmithKline (Parsippany, NJ). The vitamin D₃ was obtained from Tishcon Corporation (Westbury, NY) Comment: the trial was sponsored by the industry."
Other bias	Low risk	Comment: the trial appears to be free of other components that could put it at risk of bias.