Xing 2013.

Methods	Randomised clinical trial with parallel group design (3 groups).
Participants	75 participants (17% women), aged 28 to 65 years, mean age 48 years, undergoing liver transplantation. Inclusion criteria: primary liver transplant recipients. Exclusion criteria: history of corticosteroid, anticonvulsant, or vitamin D intake; renal disease.
Interventions	Intervention 1: calcitriol 0.25 μg/day + calcium gluconate (n = 25). Intervention 2: calcium gluconate (n = 25). Control: placebo (n = 25). For 1 month.
Outcomes	Outcomes reported in abstract of publication: Primary outcomes: acute cellular rejection rate at 1 month' post transplant. Secondary outcomes: none stated.
Stated aim of study	To investigate effects of calcitriol on acute cellular rejection rate of liver transplant recipients.
Notes	Study sponsored by a grant from Shanghai Nature Science Fund project and a grant from Science and Technology Department of Shanghai. Additional information received through personal communication with the authors on 13 February 2014.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method of sequence generation not specified.
Allocation concealment (selection bias)	Unclear risk	Method used to conceal allocation not described so that intervention allocations may have been foreseen in advance of, or during, enrolment.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Insufficient information to permit judgement of 'low risk' or 'high risk'.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Insufficient information to permit judgement of 'low risk' or 'high risk'.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Missing data unlikely to make treatment effects depart from plausible values.
Selective reporting (reporting bias)	Unclear risk	Unclear whether all predefined and clinically relevant and reasonably expected outcomes were reported.
For‐profit bias	Low risk	Trial appeared to be free of industry sponsorship or other type of for‐profit support that could manipulate the trial design, conductance, or trial results.
Other bias	Low risk	Trial appeared to be free of other factors that could put it at risk of bias.