Rianthavorn 2013.

Methods	Study design: RCT Time frame: not reported Follow‐up period: not reported Loss to follow‐up/excluded: none reported
Participants	Country: Thailand Setting: university teaching hospital Aged < 18 years. CKD stage 5/5D, vitamin D deficiency with levels < 30 ng/mL, Hb level 10.0 to 12.5 g/dL, serum phosphorus, 6.5 mg/dL, corrected Ca < 10.5 mg/dL, Ca x P, 65mg2/dL2 one month prior to recruitment Number: treatment group (10); control group (10) Mean age ± SD (years): treatment group (7.1 ± 5.4); control group (9.3 ± 5.3) Sex (M/F): treatment group (7/3); control group (6/4) Exclusion criteria: thalassaemia; chronic liver disease; gastrointestinal malabsorption; significant blood loss; PTH > 800 pg/mL; proteinuria > 2 mg/mg of urine creatinine; blood transfusion; chronic anticonvulsant therapy; prior ergocalciferol supplementation and kidney transplantation
Interventions	Treatment group Severe vitamin D deficiency (serum 25D level < 5 ng/mL) 40,000 IU ergocalciferol weekly for 4 weeks, then 40,000 IU every second week for 8 weeks (total 320,000 IU ergocalciferol) Mild deficiency (serum 25D level 5 to 15 ng/mL) 40,000 IU ergocalciferol every second week for 12 weeks (total 240,000 IU ergocalciferol) For 25D insufficiency (serum 25D levels 16 to 30 ng/mL) 40,000 IU ergocalciferol every 4 weeks for 12 weeks (total 120,000 IU ergocalciferol) Control group No specific therapy Co‐interventions Calcium carbonate for phosphate binding with phosphorus level > 5.5 mg/dL Alfacalcidol for secondary hyperparathyroidism Anaemia management: epoetin alfa administered subcutaneously
Outcomes	Ca levels PTH levels Phosphorous levels
Notes	Primary outcome was the effect of ergocalciferol on ESA dose
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Simple randomisation, randomisation was sequentially done (information from authors)
Allocation concealment (selection bias)	High risk	Simple randomisation, randomisation was sequentially done (information from authors)
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not blinded and lack of blinding could affect patient management
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Laboratory outcome and unlikely to be influenced by lack of blinding
Incomplete outcome data (attrition bias) All outcomes	Low risk	All patients completed 12 week therapy
Selective reporting (reporting bias)	Low risk	All prespecified outcomes mentioned
Other bias	Unclear risk	Insufficient information to permit judgement