Lactase deficiency means: Lactase deficiencies: Insufficient lactase production in the small intestine. The enzyme lactase helps to break down lactose which is a sugar that can be found in dairy products, milk, and other dairy products. It also serves as an ingredient in many other food recipes. While most people have the capacity to produce adequate levels of lactase from birth, there is a significant difference in the lactase production between ethnic groups. Many people of African and Asian descent have trouble digesting lactose-containing products. Diarrhea, gas, and bloating are the most frequent symptoms of lactase deficiencies. The best treatment is to avoid lactose from the diet, or take over-the-counter Lactase Supplements before you eat foods that have lactose.
(in Medical Dictionary)