The first 1,000 days of life are a critical window for brain development, during which nutrition—particularly micronutrients—plays a vital role. Breast milk is the primary source of nutrition in early infancy, but lactation increases maternal micronutrient demands by about 50%, heightening the risk of deficiencies that can lead to long-term neurological impairment. Micronutrient deficiencies are prevalent in lactating women and infants in low- and middle-income countries (LMICs) where food insecurity and lack of dietary diversity contribute to nutritional challenges.  In Ethiopia, 28.6% of lactating women are anemic and 28% of children have at least one micronutrient deficiency. The use of a multiple micronutrient supplement (MMS) during lactation is a promising strategy to increase micronutrient content in breast milk and improve the micronutrient status in the mother and infant. While prenatal MMS has been shown to improve birth outcomes, research on its use during lactation is limited. Rigorous studies are needed to determine the impact of MMS during this critical period and to guide recommendations on its use across the pregnancy-to-lactation continuum.

The Ethiopia Micronutrient Supplementation Enhancing Child Health and Thriving (EMECHAT - "እመጫት" or “Nursing Mother”) study is an individually randomized, parallel, open-label, controlled trial that will investigate the effect of postnatal Multiple Micronutrient Supplementation (MMS) on maternal breast milk composition and child neurodevelopmental outcomes in Addis Ababa, Ethiopia. Lactating postpartum mothers will be randomized to receive daily MMS or routine postnatal care. We will enroll 600 mothers who have recently given birth and plan to exclusively breastfeed for 4–6 months. The primary study outcome is infant brain resting electroencephalography and behavioral measures of neural function.