Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: “The computerised block randomisation scheme was done with a block size of 20, so that in each block ten infants received vitamin A and ten received placebo”
		Comment: Most likely done
Allocation concealment (selection bias)	Low risk	Quote: “An independent statistician who was not part of the trial prepared the randomisation code at the WHO offices in Geneva, Switzerland. The code was available only to the Data Safety and Monitoring Board (DSMB) and their statistician”
		Comment: Most likely done
Blinding of participants and personnel (performance bias)	Low risk	Quote: “The research team and parents were fully unaware of the content of the capsules, which were only labelled with the infant number. Amanufacturer (StridesArcolab Limited, Bangalore, India) supplied the capsules. Separate staff, who were not part of the trial, labelled all capsules”
		Comment: Most likely done
Blinding of outcome assessment (detection bias)	Unclear risk	Quote: "…"
		Comment: Most likely done
Incomplete outcome data (attrition bias)	Low risk	Quote: “Our loss to follow‐up was only 1.1% at the time of ascertainment of our primary outcome at 6 months and only 2.9% at 12 months”
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