Lactase is an enzyme needed to convert milk sugar (lactose) into simple sugars that the body can use (glucose and galactose). Lactase is produced in the small intestine.


Production of lactase is highest at birth in full-term infants. It begins to decrease at about age 3. Lactose intolerance is common in adults. As their small intestines produce less lactase, most people naturally decrease the amount of lactose they eat or drink. Lactase production may also decline temporarily in response to damage of the intestinal lining, which can occur from a gastrointestinal illness.

Current as of: February 12, 2016

Author: Healthwise Staff
