The purpose of this study is to determine to what extent supplementation with zinc and other micronutrients are efficacious in preventing malaria in young Tanzanian children.

Zinc is essential for the functioning of the immune system. Supplementation trials in Asia, Latin America, the Pacific and developed countries have shown that increasing zinc intake has great potential to control common infections in children, but the response to supplementation may be different in Africa, where the primary environmental challenge to children's health is malaria. Simultaneous supplementation with other potentially limiting nutrients may be required to overcome a lack of response when zinc is given alone. The project aims at measuring effects of daily oral supplementation with zinc and other micronutrients, given either alone or in combination, on malaria incidence and nutritional status, and on indicators of immunity.

Inclusion Criteria:

• Aged 6-60 months
• Permanently residing in the study area
• Being moderately or mildly stunted (height-for-age z-score <-1.5 SD)
• Informed consent from parents or guardians obtained

Exclusion Criteria:

• Severe wasting (weight-for-height z-score <-3 SD)
• Hemoglobin concentration <70 g/L
• Axillary temperature ≥37.50 °C with malaria antigenemia
• Signs and symptoms at randomisation suggesting malaria, hepatitis, HIV/AIDS, tuberculosis, sickle cell disease or other severe condition
• Unable to produce a venous blood sample (>1 mL)