lactose intolerance is more common in some ethnic groups than in others. the national institute of diabetes and digestive and kidney diseases estimates that up to 75% of all adult african americans and native americans and 90% of asian americans are lactose intolerant. as people age their bodies produce fewer lactase enzymes so most people don't have symptoms until they are adults. most people inherit the condition from their parents. lactose intolerance is not very common in children under two years of age unless the child has a lactase deficiency because of an injury to the small intestine. if you think your infant or child may be lactose intolerant talk to your child's pediatrician.
who becomes lactose intolerant?