Background: Mineral micronutrient deficiencies are common in sub-Saharan Africa, where diets are monotonous and dominated by starchy staples. Recent surveys have revealed substantial spatial variation in the micronutrient composition of cereals in Ethiopia, associated with soil and environmental factors. Single national micronutrient concentration values for cereal grains are therefore of limited use for estimating typical micronutrient intakes. We combined spatially disaggregated cereal production and composition data to estimate the dietary supply of micronutrients from staple cereals at district-level in the Amhara, Oromia, and Tigray regions of Ethiopia.

Methods: District-level cereal production data were derived from the national agricultural sample survey. The mean grain calcium (Ca), iron (Fe), selenium (Se), and zinc (Zn) composition of cereals in each district was estimated from GeoNutrition survey data. Dietary micronutrient supply from cereals was calculated assuming cereal consumption of 300 g capita^-1 day^-1, with cereal type proportional to district production quantity.

Results: Barley (Hordeum vulgare L.), maize (Zea mays L.), sorghum (Sorghum bicolor (L.) Moench), teff (Eragrostis tef (Zuccagni) Trotter), and wheat (Triticum aestivum L.) represented 93.5% of total cereal production in the three regions. Across districts the average supply of Ca, Fe, and Zn from cereals was 150, 23, and 7 mg capita^-1 day^-1, respectively, and 25 µg capita^-1 day^-1 for Se. At district-level, the combinations of cereals grown varied as did their composition, leading to a large range in the estimated contribution of cereals to dietary requirements, i.e., for an adult woman: 1–48% Ca, 34–724% Fe, 14–191% Se, and 48–95% Zn.

Conclusion: There was considerable variability in the dietary supply of Ca, Fe, Se, and Zn from staple cereals between districts of Ethiopia. Disaggregated dietary nutrient supply data has potential value in quantifying risks of dietary micronutrient deficiencies and informing interventions to tackle micronutrient malnutrition.

Key words: Cereals; dietary supply; mineral micronutrients; disaggregated data, spatial data