Cow's Milk Allergy (CMA) is the name used to cover several adverse reactions to its protein components. Caseins and whey proteins mediate the reaction. α-lactalbumin and β-lactoglobulin can trigger allergy through a specific immune response mediated or not by immunoglobulin E (IgE). Breastfeeding is a feeding mechanism, but it is also a key element in overcoming this type of allergy, using adequate feeding of the mother that allows for achieving oral tolerance. Breastfeeding provides sufficient nutrition and the development of the intestinal microbiota. Developing the microflora and the process of oral tolerance mediated by breastmilk is key, as it also provides a minimal load of allergens, as demonstrated even in model organisms such as mice. This topic must be shared to offer nutrition experts, doctors, and parents the correct way to feed a nursing child to recover from a milk protein intolerance. The review provides the technical background of the pathology.