Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: “This was a cluster randomized, placebo‐controlled trial”; and “an external consultant generated the computerized allocation sequence of clusters to each study intervention to either group using Epi Info 3.5.3 with restricted randomization based on population size, expected births and LHW presence”
Allocation concealment (selection bias)	Low risk	Quote: “An external consultant generated the computerized allocation sequence of clusters to each study intervention to either group using Epi Info 3.5.3 with restricted randomization based on population size, expected births and LHW presence”
Blinding of participants and personnel (performance bias)	Low risk	Quote: “The capsules were identical in appearance (Banner Pharmacaps, Canada) and supplied through the courtesy of the Micronutrient Initiative (Ottawa, Canada). The capsules were packaged in containers labelled as A & B. The content of the capsules were masked from field staff and supervisors, and the codes were only known to the external consultant responsible for cluster randomizations and the chair of the DSMB. The masking was maintained until the completion of the study”
Blinding of outcome assessment (detection bias)	Low risk	Quote: “The capsules were identical in appearance (Banner Pharmacaps, Canada) and supplied through the courtesy of the Micronutrient Initiative (Ottawa, Canada). The capsules were packaged in containers labelled as A & B. The content of the capsules were masked from field staff and supervisors, and the codes were only known to the external consultant responsible for cluster randomization and the chair of the DSMB. The masking was maintained until the completion of the study”
Incomplete outcome data (attrition bias)	Low risk	Quote: “We were able to follow 10,286 (93%) infants until death or 6 months of age”
Selective reporting (reporting bias)	Low risk	Author seem to report all the relevant outcomes
Other bias	Low risk	No other risk of bias was noted