Soemantri 1997.

Methods	Randomised controlled trial. 2‐arm design with individual randomisation.
Participants	97 children, both sexes (sex distribution not reported), aged 7‐11 years, attending the primary school Batang, in Indonesia. Inclusion criteria: anaemia (Hb below 120 g/L); not taking iron supplements during the last six months; no evidence of hepatosplenomegaly, haemoglobinopathy, acute or chronic disease, severe anaemia. Baseline prevalence of anaemia: 67.36%. Socioeconomic status not reported.
Interventions	Children were divided into 2 groups and randomly assigned Group 1 (n = 52): children received daily 3 mg of iron per kilogram (as ferrous sulphate); Group 2 (n = 45): children received once a week 3 mg of elemental iron per kilogram (as ferrous sulphate) (approximately 85 mg of iron per week). Length of the intervention: 3 months.
Outcomes	Anthropometric measurements (weight for age Z‐score, height for age Z‐score) and haemoglobin.
Notes	The solutions were given by the school teachers on school days with careful supervision. All children with intestinal parasites were treated prior to supplementation. Z‐scores used the National Center for Health Statistics data as a reference. Malaria endemicity not reported.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Children were randomly assigned to the study groups. Method of sequence generation not described.
Allocation concealment (selection bias)	Unclear risk	Not described.
Blinding (performance bias and detection bias) All outcomes	High risk	Participants: not reported. Personnel: not reported. Outcome assessors: not reported.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Two children (3.8%) were excluded from the daily group because of gastrointestinal side effects.
Selective reporting (reporting bias)	Unclear risk	There is insufficient information to permit judgement.
Other bias	Low risk	The study appears to be free of other sources of bias.