Sood 1975.

Methods	Trial conducted in New Dehli and Tamil Nadu, India. Dates of study: not reported
Participants	Pregnant women with gestational age 22 ± 2 were eligible to participate in the trial. A total of 647 pregnant women participated in the trial. Women with chronic diseases like heart diseases, tuberculosis, leprosy, chronic diarrhoea and a Hb < 5 g/100 mL were excluded from the study.
Interventions	There were total of 7 study groups. 2 in the control group and 5 in the intervention group. Intervention Intervention groups 1‐4 received vitamin B12, folic acid and iron in a range of 30 to 240 mg Itervention group 5 received 120 mg of iron without vitamin B12 and folate Control Control group 1 received placebo Control group 2 received vitamin B12 and folic acid alone Supplementation was given for 10‐12 weeks.
Outcomes	Outcomes were improvement in maternal Hb/haematocrit, iron absorption from maternal gut, fetal birthweight, maternal and fetal Hb 3 months postpartum, hookworm infestation in mother and side‐effects of supplementation
Notes	None of the outcomes were reported in a format that allowed inclusion of the data in this review. Declarations of interest: not reported Funding sources: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "By reference to previously prepared random tables the women were allocated to one of the two streams A or B" and "within each stratum subjects were allotted to final treatment groups according to a set of random numbers" Comment: probably done
Allocation concealment (selection bias)	High risk	Quote: "By reference to previously prepared random tables the women were allocated to one of the two streams A or B" and "within each stratum subjects were allotted to final treatment groups according to a, set of random numbers" Comment: probably not done
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "All the tablets had the same appearance and had the daily folic acid and iron dose divided into two tablets". Comment: participants, caregivers probably blinded to the treatment assignment.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "All the tablets had the same appearance and had the daily folic acid and iron dose divided into two tablets". Comment: outcome assessors probably blinded to the treatment assignment.
Incomplete outcome data (attrition bias) All outcomes	High risk	Attrition was 30% and reasons for it were reported.
Selective reporting (reporting bias)	Low risk	Comment: all outcomes mentioned in the methods section were presented in the paper
Other bias	Low risk	Comment: no other bias was identified