Q. Your recent column on temporal arteritis didn't mention something my wife and I have been wondering about. She has to take the steroid prednisone to keep this condition under control. But we're worried about the long-term side effects of prednisone, especially osteoporosis and bone fractures. Other than taking calcium, what else can she do to prevent osteoporosis?

A. You're right to be concerned about the long-term side effects of steroid medicines such as prednisone. In addition to osteoporosis, they can lead to high blood pressure, glaucoma, cataracts, stomach ulcers and confusion. They can also increase your risk of infections and promote development of diabetes. Among people taking steroids long-term, more than one in four will suffer a bone fracture due to osteoporosis.

You can lower your risk of side effects by taking the lowest effective dose for the shortest amount of time. In some cases, you can take the prednisone every other day, instead of every day, which will also lower your risk. And to help prevent osteoporosis, or to treat it if it does occur, there are several options.

In 1996, the American College of Rheumatology issued guidelines on preventing and treating osteoporosis in people taking steroid medicines for stretches of six months or more. The treatment varies depending on whether you're a man or a woman and, if you're a woman, whether you have reached menopause.

One point to keep in mind is that you lose calcium from your bones most rapidly during the first six months of steroid therapy. And the higher the dose you take and the longer you take it, the more calcium you lose. Even low doses, in the range of 7.5 milligrams a day, will lead to osteoporosis if taken long enough. (Prednisone doses of 40 milligrams or higher are considered to be in the high range.)

The best treatment is prevention, meaning you should try to keep from losing calcium from your bones in the first place. It's harder to restore your bones to normal strength once they've lost calcium and developed osteoporosis.

To check your bones, your doctor can order a type of CT scan known as a DEXA scan. This will give an idea of whether your bones are normal, whether they have a somewhat reduced amount of calcium or whether the bone loss is severe enough to be osteoporosis.

To prevent osteoporosis, you can try several measures that don't involve taking any medication. These include not smoking, limiting alcohol consumption and--if your doctor approves--doing weight-bearing exercises for 30 to 60 minutes a day.

Increasing calcium and vitamin D either through diet or supplements is generally considered to be a safe and effective way to combat osteoporosis, though it may not be enough to help people taking high-dose steroids.

Hormone replacement therapy can help women who have reached menopause. This means taking estrogen and, if you have a uterus, a progestogen to protect against a small risk of cancer of the uterus. Women who have not reached menopause can take estrogens in the form of birth control pills.

If you can't take estrogens, you can take a medicine that helps restore calcium to bones. It's called Fosamax (alendronate). Another option is calcitonin, a hormone made by your body.

Some people taking long-term steroids lose calcium through their urine. To test for this, your doctor might measure the amount of calcium in a 24-hour collection of urine. If the calcium is high, you can take a thiazide fluid pill, such as HCTZ. Even though it's a fluid pill (diuretic), it keeps the body from losing calcium.

Jay Siwek, chairman of the department of family medicine at Georgetown University Medical Center, practices at the Fort Lincoln Family Medicine Center and Providence Hospital in Northeast Washington.

Consultation is a health education column and is not a substitute for medical advice from your physician. Send questions to Consultation, Health Section, The Washington Post, 1150 15th St. NW, Washington, DC 20071. Questions cannot be answered personally.