Critical Nutrients in Ketogenic Diets for Infants and Children Under Ten Years of Age—A Hypothetical Study

Background: Ketogenic diets can treat drug-resistant epilepsy, even in early childhood. However, due to the severely restricted food selection, there is an assumed increased risk of inadequate micronutrient intake. Currently, the available data is limited. Methodology: Optimized daily meal plans were created for infants and children aged 1–9 years (physical activity level; PAL 1.6) in three ketogenic ratios (3:1, 2:1, 1:1). Compliance with reference values for micronutrients (≥95%) was analyzed using the reference values of the German and Austrian Nutrition Societies (DGE/ÖGE) and PRODI® nutrition software (Germany). Results: Vitamin D never reached more than 25% of the reference values in any age group or ratio, and pantothenic acid consistently remained at around 40–70%. At the 3:1 and 2:1 ratios, the mean values for vitamins B1, B2, and B12, as well as for calcium, zinc, iron, and fiber, were all below 95% of the reference values. Although the 1:1 ketogenic ratio was more nutrient-dense, this only partially compensated for potential deficiencies. Conclusions: The results illustrate a limited micronutrient supply dependent on the ratio in ketogenic diets for infants and children. Careful food selection and nutritional therapy support are necessary to avoid potential nutrient gaps.