Wissing 2005.

Methods	Study design: open‐label, parallel RCT Duration of study: January 1999 to August 2000 Duration of follow‐up: 12 months
Participants	Country: Belgium Setting: single centre Inclusion criteria: all patients receiving a kidney transplant Number: treatment group (38); control group (41) Mean age ± SD (years): treatment group (43.0 ± 12.3); control group (42.7 ± 14.8) Sex (M/F): treatment group (23/15); control group (22/19) Exclusion criteria: hypercalcaemia; graft loss; unwillingness to provide informed consent
Interventions	Treatment group Cholecalciferol (oral): 25,000 IU/month 12 months Control group No treatment Co‐interventions Calcium carbonate or calcium acetate
Outcomes	Hypercalcaemia (equal or greater than 2.4 mmol/L) BMD at lumbar spine and femoral neck Acute graft rejection
Notes	Funding source: not reported Trial registration: not applicable as published before end of 2005
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Alternate allocation
Allocation concealment (selection bias)	High risk	Alternate allocation
Blinding of participants and personnel (performance bias) All outcomes	High risk	Unblinded study
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Insufficient information to permit judgement
Incomplete outcome data (attrition bias) All outcomes	High risk	11/90 participants lost to follow‐up
Selective reporting (reporting bias)	High risk	Patient‐centred outcomes not reported systematically
Other bias	Unclear risk	No additional threats to validity identified

ACR ‐ albumin‐creatinine ratio; BMD ‐ bone mineral density; CNI ‐ calcineurin inhibitor/s; CrCl ‐ creatinine clearance; DEXA ‐ dual energy X‐ray absorptiometry; DGF ‐ delayed graft function; DM ‐ diabetes mellitus; (e)GFR ‐ (estimated) glomerular filtration rate; GI ‐ gastrointestinal; HD ‐ haemodialysis; HIV ‐ human immunodeficiency virus; M/F ‐ male/female; MMF ‐ mycophenolate mofetil; PRA ‐ panel reactive antibody; (i)PTH ‐ (intact) parathyroid hormone; RAAS ‐ renin‐angiotensin‐aldosterone system; RAS ‐ renin‐angiotensin system; RCT ‐ randomised controlled trial; SC ‐ subcutaneous; SCr ‐ SCr; SD ‐ standard deviation; UACR ‐ urinary albumin:creatinine ratio; UPCR ‐ urinary protein:creatinine ratio