Marcen 2010.

Methods	Study design: open‐label, parallel RCT Study duration: not reported Duration of follow‐up: 6 to 12 months
Participants	Country: Spain Setting: not reported Inclusion criteria: kidney transplant recipients with vitamin D insufficiency or deficiency Number: treatment group (36); control group (34) Mean age ± SD (years): not reported Sex (M/F): 38/32 Exclusion criteria: not reported
Interventions	Treatment group Cholecalciferol: 400 IU/d Calcium supplements: 600mg/d Control group No treatment Co‐interventions Not reported
Outcomes	iPTH Vitamin D
Notes	Abstract‐only publication with outcomes of interest not reported Funding source: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Insufficient information to permit judgement
Allocation concealment (selection bias)	Unclear risk	Insufficient information to permit judgement
Blinding of participants and personnel (performance bias) All outcomes	High risk	Open‐label study
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Insufficient information to permit judgement
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Insufficient information to permit judgement
Selective reporting (reporting bias)	High risk	Data unable to be meta‐analysed
Other bias	Unclear risk	Insufficient information to permit judgement