Lactase is a digestive enzyme produced by cells lining the small intestine. It is also a compound sugar, which is made by the joining of galactose and glucose, two simple sugars, in the body. Lactase is essential for the body to break down lactose, the sugar that occurs naturally in milk and dairy products. Lactose intolerance, or the inability to digest foods containing lactose, is a direct result of lactase deficiency.

Lactase deficiency can occur from birth, also known as congenital absence, due to a mutation of the specific gene that is responsible for its production. This only happens in rare cases, and would be identified shortly after birth. Diseases which destroy the lining of the small intestine may also cause a deficiency, by destroying the cells’ ability to produce the enzyme. However, the most common cause of lactase deficiency is adult-type hypolactasia, or the reduced production of lactase after infancy.

Most people do not retain high levels of lactase production into adulthood. The body produces more of the enzyme during infancy, when the diet consists of mostly milk. Only a third of all people are able to digest lactase properly as adults, making most people susceptible to lactase deficiency and lactose intolerance.

There is no treatment that can enhance the body’s ability to produce lactase. However, the problem can be controlled easily through diet and lifestyle changes. Avoiding milk, drinking lactose-reduced milk, which is created by adding lactase, or using lactase tablets, capsules, and drops, can help prevent discomfort caused by lactose intolerance.

Lactase is produced commercially for use in milk, to make it more easily digestible by lactose intolerant individuals. Yeast, fungi, and certain bacteria create their own lactase naturally, which is collected in a laboratory and made into different supplements. The resulting products are lactase capsules, drops, or tablets that can be taken directly, or added to lactose containing foods, prior to consuming.

Lactase is safe to take, and no known side effects exist. There are also no known drug interactions, and it is available without a doctor’s prescription. The amount needed to prevent symptoms of lactose intolerance will vary depending on the specific food, and how much lactose the body currently produces. Milk, ice cream, and yogurt contain the greatest amounts of lactose, so more lactase must be added. A qualified medical professional will be able to recommend a proper dosage for the specific individual.