Eke 1983.

Methods	Study design: parallel RCT Time frame: 1981 to 1983 Follow‐up period: 12 months Loss to follow‐up/excluded: 6% (1/16)
Participants	Country: UK Setting: single centre GFR 20 to 50 mL/min/1.73 m2 Number: treatment group (8); control group (8) Mean age: 10.4 years Sex (M/F): not reported Exclusion criteria: previously treated with vitamin D or its analogues
Interventions	Treatment group Oral 1α‐hydroxyvitamin D: 10 ng/kg/d for 1 year Control group Oral calciferol: 670 ng/kg/d for 1 year Co‐interventions Aluminium hydroxide as phosphate binder
Outcomes	Change in GFR measured by 51Cr EDTA Bone histology, BMD X‐ray changes Ca, phosphorus, ALP Number with hypercalcaemia
Notes	Graphical data only for changes in GFR, Ca, phosphorus and PTH No clear numerical data for BMD, X‐rays, ALP
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Said to be "double‐blind" study but no other information provided
Allocation concealment (selection bias)	Unclear risk	No information provided
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Said to be double‐blind but no other information provided
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Outcomes are laboratory based and unlikely to be influenced by blinding
Incomplete outcome data (attrition bias) All outcomes	Low risk	One patient excluded when commenced RRT but this unlikely to influence results
Selective reporting (reporting bias)	High risk	No reporting of actual numbers for outcomes of GFR, PTH and other biochemistry
Other bias	Low risk	Leo Laboratories provided medications