With the launch of my newest book, Outwitting Osteoporosis, I'm hearing from folks who want to know what they can do, besides using the dairy products I recommended, to get the calcium necessary to help keep their bones strong. Because I can't resist an opportunity to find out what's behind the questions I'm asked, I often respond with a question of my own: Why do you ask?

The most frequent response is, "I'm allergic to milk."

Although many people claim to have a milk allergy, what they usually have is lactose intolerance. It's important to know the difference.

A true allergy of any kind is caused by an abnormal response of the body's immune system to a protein in the environment. True milk allergy is fairly uncommon and occurs mostly in children who get hives, breathing problems, or other difficulties when they drink milk. Most people (including my son) grow out of a milk allergy as they grow older. Lactose intolerance, on the other hand, is the inability to digest significant amounts of lactose, the predominant sugar of milk. This inability results from a shortage of the enzyme lactase, which is normally produced by the cells that line the small intestine. Lactase breaks down milk sugar into simpler forms that can then be absorbed into the bloodstream. When there is not enough lactase to digest the amount of lactose consumed the result is bloating, gas and diarrhea within 2 hours of consuming the milk.

Lactose intolerance is more common among non-Caucasians and becomes more common as we age. A lactase pill (Lactaid) sold in pharmacies can be taken with milk to prevent the symptoms of a true lactose intolerance. Even folks with a true lactose intolerance can usually eat yogurt or cheese without getting a reaction, but most cases of self-diagnosed intolerance are suspect. For example, in a controlled study where people claiming to have lactose intolerance were given cow's milk without knowing it, the majority did not show any symptoms. When they were given lactose-reduced milk but told it was regular cow's milk, many experienced stomach upsets. This shows the power of suggestion can be stronger than a physical cause.

There are other ways besides milk to get the calcium you need but folks who avoid milk really need to work with a dietitian to get the other nutrients milk and milk-based products provide. No, I don't work for the dairy council. I'm simply in the business of attempting to make it easy for us to get the nutrients we need from the healthy food and beverages that are easily available. Milk is one of them.

P. S. Skim milk has slightly more calcium in it than whole milk.

For more on lactose intolerance go to: http://www.niddk.nih.gov/health/digest/pubs/lactose/lactose.htm