Tanumihardjo 2002.

Methods	RCT.
Participants	Inclusion criteria: pregnant women in the second or early third trimester; 18 to 37 years old; parity from 0 to 4 children.
Interventions	Intervention group 1: 5 women received 1.07 mmol (60 mg) ferrous sulphate with a vitamin A placebo daily for 8 weeks. Intervention group 2: 8 women received vitamin A plus iron. Intervention group 3: 7 women received 8.4 µmol (8000 IU) vitamin A as retinyl palmitate with an iron placebo. Control group: 7 women received placebo.
Outcomes	Maternal Hb and retinol levels.
Notes	Vitamin A levels were measured before starting supplementation. Country: Indonesia. Study setting: local health posts the suburban areas of Bogor in West Java.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No information provided.
Allocation concealment (selection bias)	Unclear risk	No information provided.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	"Subjects and village volunteers were unaware of group assignment."
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No information provided.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No loss of follow‐up reported.
Selective reporting (reporting bias)	Unclear risk	The protocol of the study is not available at the moment.
Other bias	Unclear risk	Not enough information provided.