Sagheb 2012.

Methods	Study design: 4‐arm parallel RCT Study duration: March 2008 to February 2009 Study follow‐up period: 8 weeks
Participants	Country: Iran Setting: HD centre Health status: chronic stable adult HD patients with RLS diagnosed using IRLSSG questionnaire Number: treatment group 1 (15); treatment group 2 (15); treatment group 3 (15); control group (15) Mean age ± SD (years): treatment group 1 (47.4 ± 14.2); treatment group 2 (54.6 ± 15.2); treatment group 3 (49.3 ± 12.9); control group (59.5 ± 17.9) Sex (M/F): treatment group 1 (6/9); treatment group 2 (6/9); treatment group 3 (4/11); control group (9/6) Exclusion criteria: participants receiving medications known to aggravate RLS such as tricyclic antidepressants, selective serotonin reuptake inhibitors, dopamine antagonists, dopamine blocking antiemetics, lithium, and sedative antihistamines; history of kidney stones were excluded due to concerns over increased risk of oxalosis and its joint and vascular complications in HD patients who consume vitamin C
Interventions	Treatment group 1 Vitamin C 200 mg + Vitamin E 400 mg for 8 weeks Treatment group 2 Vitamin C 200 mg + placebo for 8 weeks Treatment group 3 Vitamin E 400 mg + placebo for 8 weeks Control group Placebo for 8 weeks Co‐interventions None
Outcomes	Severity of RLS at 0 and 8 weeks and the change in the score using IRLSG scoring system (0 to 40 max) Adverse events
Notes	Funding source: grant from the Shiraz University of Medical Sciences, Shiraz, Iran
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Blocked randomisation with a fixed block size of four by randomisation sequence generator
Allocation concealment (selection bias)	Low risk	1:1:1:1 random assignment to the 4 groups; this was done by an investigator who had no clinical involvement in the study
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Double blind
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Double blind
Incomplete outcome data (attrition bias) All outcomes	Low risk	Used random sequence generating software
Selective reporting (reporting bias)	Low risk	Clear reporting of side effects. Study protocol clear enough from the methods section
Other bias	Low risk	Funded by a Grant from the Shiraz University of Medical Sciences, Shiraz, Iran