This study will determine whether the haemoglobin response to daily home fortification for 30 days with 3mg iron as NaFeEDTA is non-inferior to 12.5 mg iron as encapsulated ferrous fumarate.

Background: Fortification of local complementary foods and supplementation with micronutrient powders including iron has been shown to prevent anaemia. Iron can cause complaints (diarrhoea, constipation, etc.) related to oxidative stress in the intestine, however, and at doses conventionally used for daily supplementation, iron can increase rates of malaria and diarrhoea. A lower dose of iron (3mg/day) as NaFEEDTA can reduce these adverse effects whilst having similar or superior efficacy in improving iron status as conventional-dose iron (12.5mg) as ferrous salts.

Objective: The primary aim is to compare daily home fortification with 3mg iron as NaFeEDTA versus 12.5 mg iron as encapsulated ferrous fumarate regarding haemoglobin concentration at the end of the 30-day fortification period.

Methods: Rural children aged 12-36 months (n=324) will receive albendazole and praziquantel against helminth infections, and preventive chemotherapy against malaria with dihydroartemisinin-piperaquine. They will subsequently be randomised to daily home fortification for 30 days with sachets containing either a) 3 mg iron as NaFeEDTA; b) 12.5 mg iron as encapsulated ferrous fumarate; or c) placebo. Parents or guardians will be instructed to mix the contents of the sachets with solid or semi-solid, ready-prepared foods. Adherence will be assessed by an electronic monitoring and time-recording device in the cap of a dispensing bottle containing the sachets. At the end of the 30-day fortification period, a venous blood sample will be collected to measure indicators of iron status and inflammation. Children who received iron will continue to be followed for a maximum of 120 days after randomisation to estimate the time point when ≥10% of children has developed severe anaemia (haemoglobin concentration <70 g/L).

Inclusion Criteria:

1. Aged 12-36 months;
2. Residing in the study area;
3. Planning to be in the area for the duration of the intervention and follow-up;
4. Study protocol accepted and informed consent given by at least one parent or guardian

Exclusion Criteria:

1. Known or reported allergy to dihydroartemisinin, piperaquine, benzimidazole drugs or praziquantel;
2. A sibling from the same household already randomised to intervention;
3. Severely malnourished (weight-for-height z-score < -3 SD) (for ethical reasons);
4. Presence of fever (axillary temperature ≥ 37.5 ºC) (to avoid inflammation-induced effects on iron status markers);
5. Presence of reported or suspected systemic disorder (e.g. HIV infection, sickle cell disease) (to avoid inflammation-induced effects on iron status markers and to avoid attrition);
6. Missed one or several doses of the 3-day course of dihydroartemisinin-piperaquine (to ensure that participants are protected against malaria for the duration of the iron intervention);
7. No blood sample collected, or blood volume collected < 5 mL;
8. Haemoglobin concentration < 70 g/L (to prevent severe anaemia).