Beneficiary Role of Zinc and Iron Fortification for Foods in Under-5 Children: Supporting & Enhancing Cognitive and Physical Development During the Preschool Years

Micronutrient deficiencies, particularly iron and zinc deficiencies, represent a significant global public health challenge, especially among children under five years of age in low- and middle-income countries. Early childhood is a critical period for brain development, physical growth, and immune maturation, all of which depend on adequate micronutrient intake. Iron deficiency is the most common cause of anemia worldwide and is strongly associated with impaired cognitive development, delayed psychomotor performance, reduced attention span, and poor learning capacity. Zinc deficiency contributes to growth retardation, compromised immune function, increased susceptibility to infections, and elevated risks of morbidity and mortality in young children. Food fortification with iron and zinc has emerged as a cost-effective, scalable, and sustainable intervention to address these deficiencies at the population level. Fortifying commonly consumed staple foods and complementary foods allows for widespread micronutrient delivery without requiring major dietary behavior changes. Evidence from randomized controlled trials and national nutrition programs indicates that iron and zinc fortification can improve hemoglobin concentrations, reduce anemia prevalence, support linear growth, and enhance cognitive and motor development during the preschool years. This review evaluates the role of iron and zinc fortification in improving cognitive and physical development among under-five children, focusing on the crucial preschool period. Findings from clinical studies, large-scale fortification initiatives, and World Health Organization (WHO) guidelines are synthesized to highlight the physiological benefits of these micronutrients. In addition, key implementation challenges—such as micronutrient bioavailability, fortification selection, program coverage, quality control, and monitoring—are discussed. The review underscores the importance of well-designed fortification strategies and strong policy support in combating hidden hunger and improving child health outcomes globally.