Human milk is not a uniform body fluid, but quite the opposite, its composition changes continuously adapting to the requirements of the newborn. It can be considered as the gold standard for infants' nutrition and exclusive breastfeeding is recommended by the WHO during the first months of life. Additionally, its composition should be used as reference or guidance for defining optimal nutrient intakes for infants that cannot be fully breastfed. In that connection, the nutritional status and dietary habits/patterns of the mother, along with certain genetic traits, exert also influence over breast milk. Considering all these facts, and their great impact on (present and future) infant health, detailed information of breast milk composition is required for specific populations, covering as many factors, elements and nutrients as possible.