Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Randomisation was at the individual level, stratified by geographical area in blocks of four. Because births were likely in a variety of locations, randomisation was conducted at the time of recruitment"
		Comment: Most likely done
Allocation concealment (selection bias)	Low risk	Quote: "Treatment codes were kept in a sealed envelope in a locked filing cabinet in Baltimore"
		Comment: Most likely done
Blinding of participants and personnel (performance bias)	Low risk	Quote: "Investigators, study staff, and mothers were masked to the assigned treatment"
		Comment: Most likely done
Blinding of outcome assessment (detection bias)	Unclear risk	Quote: "Project staff visited the household every 2 weeks to assess the vital status of the child and any morbidity.
		"Investigators, study staff, and mothers were masked to the assigned treatment"
		Comment: Most likely done
Incomplete outcome data (attrition bias)	Unclear risk	Total number of loss to follow up: 143 (1.1%)
		The loss to follow up was not balanced
Selective reporting (reporting bias)	Low risk	Authors seem to report all the relevant outcomes
Other bias	Low risk	No other risk of bias was noted