Most people are born with the ability to digest lactose, the milk sugar found in breast milk, cow's milk and other dairy products. Infants get almost all their nutrition from milk during their first few months of life. But as they age, many of them lose the ability to digest lactose. Depending on your child's ethnic background, his body's levels of lactase---the enzyme that digests lactose---decline between the ages of 2 and 18, causing various gastrointestinal symptoms.
Symptoms of Lactose Intolerance
Toddlers with lactose intolerance may complain of stomach cramps or a tummy ache. Some children have diarrhea or excessive gas. Symptoms usually occur within a few minutes to two hours of drinking milk, eating ice cream or cheese, or consuming other products that contain lactose.
Diagnosis
The simplest way to diagnoses lactose intolerance is to withhold milk products from your toddler for a few days and see whether the symptoms resolve. The reappearance of digestive complaints when the child drinks milk again is a strong indication that he is lactose intolerant. A doctor can perform a breath hydrogen test to make the diagnosis. In this test, the child drinks milk after fasting for eight hours and the doctor uses a gas chromatograph to measure the level of hydrogen in the child's breath. High levels of hydrogen in the breath signal poor digestion of lactose.
Treatment
Completely eliminating dairy products from your toddler's diet deprives him of essential calcium and vitamin D that he needs while bones are growing and forming. Although children can also receive calcium from vegetables such as spinach and broccoli, they may have difficulty consuming enough of these foods to get all the calcium they need. Some children can tolerate lactose in small amounts, such as a few ounces of milk at a time. Consuming dairy products with meals can help decrease symptoms. Some children do well with yogurt and other types of dairy that are lower in lactose. For children with severe symptoms, fortified orange juice and cereals can help provide the calcium and vitamin D they need.
Other Considerations
Children of Hispanic, Asian or African American descent experience lactose intolerance more often than those with Northern European ancestors. Some children retain the ability to digest lactose throughout their lives. According to Dr. Richard Grand, director of the General Clinical Research Center at Children's Hospital, Boston, almost no one develops lactose intolerance before age 2. Infants who have symptoms of lactose intolerance before this age may instead be allergic to cow's milk or formula.
