Watson 1988.

Methods	Study design: parallel RCT Time frame: 1985 to 1988 Follow‐up period: 6 months Lost to follow‐up: All completed study
Participants	Country: Canada Setting: Single centre Starting CAPD; minimal or no renal bone disease on X‐ray Number: treatment group (6); control group (6) Mean age ± SD (years): treatment (11.6 ± 6.0); control group (16.4 ± 14.0) Sex (M/F): treatment group (4/2); control group (4/2) Exclusion criteria: severe radiological or evidence of clinical bone disease
Interventions	Treatment group 1α‐hydroxyvitamin D 10‐20 ng/kg/d for 6 months Control group Standard CAPD treatment only Co‐interventions Phosphate binders; vitamins B and C supplements
Outcomes	Bone histology Serum Ca, phosphorus, ALP, PTH and aluminium levels Bone X‐rays Number with hypercalcaemia
Notes	Median derived radiological scores provided in graphical form only
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not reported
Allocation concealment (selection bias)	Low risk	Randomly allocated by sealed envelopes
Blinding of participants and personnel (performance bias) All outcomes	High risk	No blinding and lack of blinding could influence patient management
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Laboratory results and bone histology assessed by investigator unaware of treatment
Incomplete outcome data (attrition bias) All outcomes	Low risk	All patients completed study
Selective reporting (reporting bias)	Low risk	All relevant outcomes reported
Other bias	High risk	Supported by Leo laboratories

AKI ‐ acute kidney injury; ALP ‐ alkaline phosphatase; AKI ‐ acute kidney injury; BMD ‐ bone mineral density; Ca ‐ serum calcium; Ca x P ‐ calcium‐phosphorus product; CAPD ‐ continuous ambulatory peritoneal dialysis; CCPD ‐ continuous cycling peritoneal dialysis; CKD ‐ chronic kidney disease; CrCl ‐ creatinine clearance; DHT ‐ dihydrotachysterol; eGFR ‐ estimated glomerular filtration rate; HD ‐ haemodialysis; HVSDS ‐ height velocity standard deviation score; IP ‐ intraperitoneal; IV ‐ intravenous; K ‐ serum potassium; M/F ‐ male/female; PD ‐ peritoneal dialysis; PTH ‐ parathyroid hormone; SLE ‐ systemic lupus erythrocytosis; RCT ‐ randomised controlled trial; rhGH ‐ growth hormone; RRT ‐ renal replacement therapy; SDS ‐ standard deviation score