The carbohydrate in milk is called lactose. Lactose is a disaccharide, which means it is made up of two simple sugars: glucose and galactose. Lactose is the primary carbohydrate found in milk, and it is important for the nutrition of young mammals, including humans, as it provides a source of energy and aids in the absorption of minerals such as calcium. However, some individuals may be intolerant to lactose, meaning they cannot properly digest it, which can cause digestive discomfort.