Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: “Randomization into the trial is in blocks of 8, using an automated system, with the 8 groups reflecting the 8 combinations of prenatal and infancy supplements”
		Comment: Adequately done
Allocation concealment (selection bias)	Low risk	Quote: “Each box of supplement is then distinguished by a number between 1 and 8”
		Comment: Adequately done
Blinding of participants and personnel (performance bias)	High risk	Quote: “Since it is not be possible to blind the field assistants or the women to the supplement type (tablet vs. LNS); all other investigators however will not know to which group the women belong”
		Comment: Not adequately done
Blinding of outcome assessment (detection bias)	Low risk	Quote: “Since it is not be possible to blind the field assistants or the women to the supplement type (tablet vs. LNS); all other investigators however will not know to which group the women belong”
		Comment: Adequately done
Incomplete outcome data (attrition bias)	High risk	Comment: 159/620 × 100 = 25.64%
Selective reporting (reporting bias)	Unclear risk	Comment: Published protocol not found. The outcomes specified in the methodology section have been reported in the results section
Other bias	Low risk	Comment: No other potential sources of bias reported
Was the allocation sequence adequately generated?	Unclear risk
Was the allocation adequately concealed?	Unclear risk
Were baseline outcome measurements similar?	Unclear risk
Were baseline characteristics similar?	Unclear risk
Were incomplete outcome data adequately addressed?	Unclear risk
Was knowledge of the allocated intervention adequately prevented during the study?	Unclear risk
Was the study adequately protected against contamination?	Unclear risk
Was the study free from selective outcome reporting?	Unclear risk
Was the study free from other risk of bias?	Unclear risk