Q. I have a few questions about eating bran, which I use to keep my bowels regular. Do I count calories with bran or are they not absorbed? (I am on a diet.) How much bran should I use? At present I am using three to four ounces a day. Does bran cause problems with calcium absorption?

A. Fiber -- an important part of our diets -- refers to plant food substances that are not easily digested or absorbed. Fiber increases the bulk of the stool and is an aid in bowel regularity. Bran comes from the husks of grains and is a good source of fiber.

I recommend getting about 25 to 35 grams of dietary fiber daily. (Fiber is measured as dietary fiber and crude fiber; 10 grams of dietary fiber contain 2 to 3 grams of crude fiber). One-hundred-percent bran cereals have about 9 to 14 grams of dietary fiber per ounce, so your three to four ounces are plenty, especially when you take into account other sources of fiber in your diet (fruits, vegitables, whole grain breads, and nuts).

Miller's unprocessed bran, available at many health food stores, is the cheapest form of bran, but also the worst tasting. I recommend adding a few tablespoons to other cereals or mixing it with juice. Most commercial bran cereals have sugar added to make them more palatable.

An important point is that bran alone won't aid regularity unless you drink plenty of liquids -- up to two quarts a day.

Because it's not readily digested, bran doesn't add many calories to the diet. Three tablespoons of wheat bran, for example, contain about 28 calories.

Lastly, bran interferes with the absorption of calcium, zinc and iron, but ordinarily not to a significant degree unless taken in excess.

Q. How can I get more information on specific medical problems or medicines I'm taking? My doctor doesn't always have the time to answer every question I have, and I would like to do more reading on my own.

A. People are becoming more interested in educating themselves about their health. Here are a few resources I would recommend:

* A general medical reference book. I think the American Medical Association's "Family Medical Guide" (Random House) is the best. Others are "Physicians' Manual for Patients" (Times Books), "Good Housekeeping Family Health and Medical Guide" (Hearst Books) and "Family Medical Guide" (William Morrow Inc.). Visit your library or bookstore and look up a few topics in books like these to help decide which you like best.

A medication reference book. Many people are familiar with the "Physicians' Desk Reference" (PDR), but it's full of medical jargon and not practical for most people. I suggest choosing from one of these: "About Your Medicines" (U.S. Pharmacopeia Convention, 1983), "Complete Guide to Prescription and Nonprescription Drugs" by H. Winter Griffith (HP Books, 1985), "Essential Guide to Prescription Drugs" by James W. Long (Harper and Row, 1985), "Family Guide to Prescription Drugs" by Dorothy L. Smith (Pharmex Ltd. 1982), or "The Pill Book" by Harold L. Silverman (Bantam, 1982).

* Your library or bookstore. For more extensive reading, chances are you'll be able to find a book or article on most medical subjects.

* Self-helf groups and medical organizations. These can be extremely helpful sources of information and support for people with a variety of physical or emotional problems. If you don't know which organization to call for a specific problem, check with the Greater Washington Self-Help Coalition, 536-4100. They will help you find a group or organization if it's available.

Q. I think I've become "addicted" to nasal decongestants -- any time I try to stop, I can't breathe. What's going on, and what can I do about it?

A. You're suffering from the chief drawback of sprays for nasal stuffiness -- rebound congestion. The spray usually works fine for the first few days, but if you use it longer, your nose can become tolerant to its effect, and you may notice that you need to spray more and more frequently for relief.

When you try to stop the spray, your nose can become more congested than when you started, sometimes making it difficult to sleep. Rebound congestion can cause other complications, like sinus infection (acute sinusitis).

Stopping nasal decongestants can be difficult. You may need to take decongestants by mouth or steroid medications (similar to cortisone) in nasal spray or pill form. Steroids are powerful anti-inflammation drugs that control the nasal swelling and allow the nose to return to normal. For very severe cases that develop after years of nasal spray misuse, minor nasal surgery may be needed to remove the areas of swelling.

The label on nasal decongestants warns not to use them for more than three days at a time, and that's good advice. It's also a good idea not to share nasal sprays -- they might pass on a cold.