International Board of Certified Lactation Consultant (IBCLC) Practice Exam

Lactose is the primary carbohydrate found in human milk, comprising approximately 98% of its carbohydrate content. This disaccharide is made up of two simpler sugars, glucose and galactose. Lactose serves several critical purposes in the diet of infants. It is an important source of energy, contributing to the growth and development of the brain and body.

Additionally, lactose plays a role in the absorption of calcium and magnesium, which are vital minerals for an infant's development. It also supports the growth of beneficial gut bacteria, further aiding in digestion and enhancing the immune system. The specific composition of human milk, including its lactose content, is evolutionary refined to meet the unique nutritional needs of infants, setting it apart from the carbohydrate profiles found in the milk of other species.

Other options like glucose, sucrose, and fructose are present in varying amounts in different types of milk but do not constitute the primary carbohydrate in human milk. Their roles and proportions differ significantly from that of lactose. Understanding the dominance of lactose in human milk is crucial for grasping its nutritional significance for infants and for appreciating the biological specificity of human lactation.