Murray‐Kolb 2007.

Methods	Design: randomised controlled trial Randomisation: individual Trial: daily oral iron versus placebo Date of study: 1999 to 2002
Participants	Setting: communities around University Park campus of The Pennsylvania State University in State College in the USA Malaria endemicity: not stated Included: women aged 18 years to 35 years (mean age 21 years) Excluded: chronic illnesses or serious health problems, not speaking English as the primary language at home Dropouts: 39 out of 152 (26% total loss to follow‐up) Sample size: total: 113; intervention: 56, control: 57
Interventions	Intervention: 160 mg ferrous sulphate containing 60 mg elemental iron Control: placebo Duration: 16 weeks
Outcomes	Haemoglobin, iron status, anxiety and psychological scores
Notes	Compliance: 95% (determine by pill count) not divided by iron/placebo group Conflicts of interest: authors declare no conflict of interest Funded by: USDA NRICGP 99‐35200‐7610 and GCRC MO1RR10732 Other notes: cognitive endpoint data reported in figures and without errors, not extractable
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Stratified randomisation performed by using random permuted blocks
Allocation concealment (selection bias)	Low risk	Bottles coded preventing disclosure of allocated arm
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Placebo administered
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Blinded as intervention and control could not be discerned; bottles coded
Incomplete outcome data (attrition bias) All outcomes	Low risk	26% loss to follow‐up; 152 enrolled, 113 completed study
Selective reporting (reporting bias)	High risk	Endpoint data for several key cognitive outcomes not reported in study. Only shown on figures without SE/SD/CIs to enable extraction
Other bias	Low risk	The study appears free of other sources of bias