Aloia 2005.

Methods	Randomised, double‐blind, placebo‐controlled trial using parallel group design (two intervention groups).
Participants	Country: United States. Number of participants randomised: 208 healthy calcium‐replete, black postmenopausal African American women, 50 to 75 (mean 60) years of age. African American ancestry of the participants was assessed by self‐declaration that both parents and at least three of four grandparents were African American. Inclusion criteria: ambulatory postmenopausal African American women not receiving hormone therapy. Exclusion criteria: previous treatment with bone active agents and any medication or illness that affects skeletal metabolism.
Interventions	Participants were randomly assigned to receive: Intervention group: vitamin D3 (800 IU) plus calcium (1200 to 1500 mg) daily, (n = 104); Control group: matched placebo plus calcium (1200 to 1500 mg) daily, (n = 104); for a two‐year period. After two years, the vitamin D3 dose was increased to 2000 IU daily in the intervention group, and the trial continued for an additional year. The calcium supplements were provided as calcium carbonate.
Outcomes	The primary outcome measure was the bone mineral density of the total hip.
Stated aim of study	"To examine the effect of vitamin D3 supplementation on bone loss in African American women."
Notes	"81 participants from the intervention group and 78 participants form the control group completed two years in the trial. 81 participants from the intervention group switched to vitamin D3 2000 IU daily plus 1200 to 1500 mg of calcium daily after two years. 78 participants from the control group switched to matched placebo plus 1200 to 1500 mg of calcium daily after two years. 74 participants from the intervention group completed 36 months of trial. 74 participants from the control group completed 36 months of the trial. A total of 222 adverse events were reported in the trial over three years. There were 15 serious adverse events, eight in the intervention group and seven in the control group. Mean pill count compliance was 87% ± 8% of vitamin D3 pills consumed after the randomisation visit." Vitamin D3 capsules and matched placebo capsules were custom manufactured for the trial (Tishcon Corp, Westbury, NY). Vitamin D3 content was also analysed in an independent laboratory (Vitamin D, Skin, and Bone Research Laboratory, Department of Medicine, Boston University School of Medicine, Boston, Mass). The calcium supplements were provided as calcium carbonate." Additional information on the risk of bias domains was received through personal communication with Dr John F Aloia (30.01.2009; 03.02.2009).
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Sequence generation was achieved using computer random number generation.
Allocation concealment (selection bias)	Low risk	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 (performance bias and detection bias) All outcomes	Low risk	The trial was described as blinded, the parties that were blinded, and the method of blinding was described, so that knowledge of allocation was adequately prevented during the trial.
Incomplete outcome data (attrition bias) All outcomes	Low risk	The numbers and reasons for dropouts and withdrawals in all intervention groups were described.
Selective reporting (reporting bias)	Low risk	Pre‐defined, or clinically relevant and reasonably expected outcomes are reported on.
Industry bias	Unclear risk	Vitamin D3 capsules and matched placebo capsules were custom manufactured for the trial (Tishcon Corp, Westbury, NY).
Other bias	Low risk	The trial appears to be free of other components that could put it at risk of bias.