DEAR DR. DONOHUE: I have a problem with chronic constipation. I drink approximately six to eight glasses of iced tea every day. Could the tannin in tea contribute to my constipation?

I don’t particularly enjoy plain water, so I drink tea for my fluid intake. – M.C.

ANSWER: Tea isn’t constipating you, and you can use it for your fluid intake. Constipation is having fewer than three stools a week or having stools that are hard and difficult to pass without straining.

Some new thoughts on constipation and laxatives fly in the face of what we’ve been taught. One is that an increased amount of fluid is necessary for regularity.

That advice has never been proved. People should drink enough fluid to keep themselves hydrated, and thirst can be their guide in most cases – perhaps not for the very old. The intestinal tract regulates how much fluid gets into it.

Fiber works as a constipation cure for some, but not all. Twenty-five to 30 grams (30 grams is 1 ounce) is recommended daily.

Fiber is indigestible material in foods. Fruits, vegetables and whole grains have the most. Bran, available in health food stores, is another good fiber source if you can’t get enough in food.

And if you don’t fancy bran, then products like psyllium and methylcellulose work. Names include Metamucil, and Fiberall.

You can also make your own stool softener by adding 2 cups of bran to 2 cups of applesauce and 1 cup of prune juice. Refrigerate the mix and take 1 to 3 tablespoons a day as needed. Colace and Surfak are stool softeners and can be used freely.

We learned that most laxatives should be used sparingly in order not to develop a “laxative habit.” This is another piece of advice that has been challenged. Many authorities now say it’s a myth, that the colon doesn’t become dependent on laxatives. A brand-new laxative, Amitiza, has relieved constipation for many. It’s a prescription medicine.

The booklet on constipation and laxatives gives more advice for attaining regularity. Readers can obtain a copy by writing: Dr. Donohue – No. 504, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.75 U.S./$6.75 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

DEAR DR. DONOHUE: I have high blood pressure and am on a low-salt diet. I would like to know how many milligrams of salt I can have in a day. It seems as though everything you buy has salt in it. Please give some information on this. – J.D.

ANSWER: You’re right. Just about everything has salt in it, and we eat far too much of it. Only about 11 percent of the salt we take in comes from the saltshaker on the table. Even so, take the saltshaker off the table so you’re not tempted to use it. Around 12 percent of our salt intake is part of food, a part that happens to have salt in it from nature. The rest, 77 percent, comes from processed foods like luncheon meats and from commercial soups and such foods.

Salt is sodium chloride, NaCl. The limit for salt is set at 6,000 mg a day. A better limit is 3,700 mg, the amount you should aim for and the amount that everyone would be wise to adopt. For reference purposes, one teaspoon holds 5,800 mg of salt.

Confusion arises when speaking about salt. Quite often, the salt content of food and dietary guidelines for it are given as milligrams of sodium (Na). To change milligrams of salt (sodium chloride) to milligrams of sodium, divide by 2.5. A healthy diet, one with 6,000 mg of salt, has 2,400 mg of sodium and an even healthier diet, one with 3,700 mg of salt, has 1,500 mg of sodium.

Foods that are loaded with salt include commercial soups, many of which contain 2,500 mg in one cup (1,000 mg of sodium); two slices of luncheon meats, about the same; some frozen dinners, 3,750 (1,500 sodium); a corned beef sandwich with mustard, 4,800 mg of salt (1,920 sodium).

The booklet on sodium and potassium discuses these minerals and their functions in detail. Readers can obtain a copy by writing: Dr. Donohue – No. 202, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.75 U.S./$6.75 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475. Readers may also order health newsletters from www.rbmamall.com.