Lactose intolerance is treated depending on how extreme the sensitivity to lactose in food is. In most individuals, monitoring the diet and avoiding foods with lactose helps to prevent the symptoms of lactose intolerance.

Avoidance of milk and dairy products

One of the major sources of lactose is milk from cows, goats, buffalo or sheep. People with lactose intolerance need to maintain a diary logging the foods they consume and the severity of any symptoms that arise as a result of their diet. Dairy products that may need to be avoided aside from milk and cheese include ice cream and butter, as well as other milk-based products such as salad cream, mayonnaise, cakes and biscuits.

However, the amount by which a person may need to reduce the milk or milk products in their diet depends on the severity of symptoms. For example, those with a mild-to-moderate lactose intolerance may still be able to consume small amounts of milk in their tea or coffee or eat milk chocolate for example.

Individuals may decide to substitute the milk they have an intolerance for with plant-based milk such as from soy, rice, almonds, oats, potatoes, quinoa, coconut and hazelnuts. Cheese contains lower levels of lactose than milk and may be consumed by some individuals with less severe lactose intolerance. In addition, some fermented dairy products in which lactose may already have been partially broken down by bacteria, may be more easily digested than others and individuals may wish to try, for example, probiotic milk, yoghurt, cottage cheese, edam or cheddar cheese and sour cream.

Some individuals may benefit from substituting lactase. Commercial lactase is available in liquid form (usually as drops) that can be added to milk or may be taken before a meal containing milk products. The lactase enzyme is also available in capsule or pill form.

Calcium supplementation

A person's daily calcium requirement is around 700mg. A diet that excludes milk and milk products therefore needs to be supplemented with calcium. Examples of foods that contain calcium include cabbage, broccoli, kale, dry fruits, soy, okra, almonds, brazil nuts, sesame seeds, salmon and sardines. Women who are pregnant or breastfeeding need between 1,000 and 1,300 mg of calcium each day and lactose intolerant women who are pregnant may need to supplement their diet with calcium.

Other vitamins such as vitamin D may also need supplementing as calcium can only be absorbed properly when vitamin D levels are sufficient.