Nutrition is one of the key factors shaping and determining the health of children in all periods of childhood. Rational nutrition provides adequate development of children’s organism, contributes to the prevention of a wide range of diseases, while nutritional imbalance affects not only physical health, but also all spheres of life activity. The article presents generalized data on the factors that ensure the formation of nutritional behavior of the child, discusses the issues of age physiology of preschool and school age, the peculiarities of the organization of nutrition, taking into account the attendance of educational institutions. The main trends and problems in the nutrition of children 3–10 years old are presented, as well as possible ways to solve them. The article discusses the possibilities of preventive interventions in case of unbalanced diet and/or increased nutrient requirements of the organism through the correction of diet, lifestyle and the use of combined vitamin and mineral complexes and biologically active additives both to ensure the physiological needs of the child’s organism and in the situation of deficiency.