Q (Dec 5) like milk and cheese and I know these are good sources of calcium. However, just less than half a cup of milk makes my digestive tract go crazy! I hate the idea of not being able to take dairy products for the rest of my life. Are there any solutions to my problem?

A If you have lactose intolerance, it means you are not able to fully digest lactose, which is a type of sugar present in milk products. This is due to deficiency of the enzyme lactase produced by your intestinal cells. Lactase breaks down lactose into simple sugars (glucose and galactose) for absorption. A person is considered to be lactose intolerant if he lacks lactase or experiences symptoms of lactose indigestion.

Many people have a threshold for lactose products. For most people, over-ingestion of dairy products (e.g two to three glasses of milk or five bars of chocolate) will cause symptoms of lactose intolerance.

Symptoms of lactose intolerance usually manifest 30 minutes to two hours after taking products containing lactose. When lactose is not digested, it goes down the intestinal tract to the colon, where bacteria will feed on it. This will cause bloatedness and sometimes cramps but, most commonly, diarrhoea.

You may increase your tolerance to milk products by gradually introducing them into your diet. Taking small but frequent amounts of milk products or taking them together with other foods will reduce the risk of lactose intolerance. You may also want to look out for lactose-reduced or lactose-free products available in some supermarkets.

Alternative calcium sources include calcium supplement tablets or foods like broccoli, dark-leaved vegetables, almonds and soft-boned fish like canned salmon or sardines.

Also available in the market now are lactase tablets or liquid which will help with lactose digestion. You may take the tablets before a milky snack/meal or add the liquid to milk before ingesting.

Probiotics can help to reduce diarrhoea as they are good bacteria present in your intestines which may also help in the digestion of lactose.

It will be handy to carry anti-diarrhoeal pills if you are lactose intolerant in case of accidental ingestion of lactose.

More information and advice can be obtained from your pharmacist. Send your questions to sthealth@sph.com.sg. This series is brought to you by Unity NTUC Healthcare and Pharmaceutical Society of Singapore.

CHONG LEE FONG. PHARMACIST, PHARMACEUTICAL SOCIETY OF SINGAPORE