There is controversy regarding malabsorption of lactose by the infant and child and the desirability of encouraging milk consumption in different age and ethnic groups. In the view of some investigators, research on lactose malabsorption is overreported and overinterpreted.
The uncertainties arise primarily from the lack of correlation between lactase deficiency and milk intolerance. Clinical symptoms, such as bloating, gaseousness, abdominal pain, and cramps, are hard to assess objectively, especially in infants and young children. Other concerns include the quantity of milk or lactose that is needed to produce symptoms in children who are lactase deficient, and the fact that the large amounts of lactose administered in the lactose tolerance test (2 g/kg or 50 g in older children) are rarely encountered in real life. For example, a 10-year-old child weighing 32 kg would have to ingest at least 1,000 ml of milk, in one sitting, to approximate the amount