DEAR DR. DONOHUE: I was turned down for giving a blood donation due to low hemoglobin. My count was 11.2. I have been a vegetarian for more than 20 years and have never had a problem until now. I eat a fair amount of green leafy vegetables and have raisins every morning. What can I do to fix this problem? – B.H.

ANSWER: Hemoglobin is the stuff inside red blood cells that grabs onto oxygen as blood passes through the lungs and releases it when blood circulates to parts of the body in need of oxygen. The hemoglobin count serves as a measure of red blood cell numbers. A low count indicates anemia. For a woman, the normal hemoglobin count is 12 to 16 g/dL (7.4 to 9.9 mmol/L), and for men, 13.5 to 17.5 (8.4 to 10.9). You are a bit on the low side, and that indicates a slight anemia.

Vegetarianism and anemia do not go hand in hand. Most people on this planet subsist on a vegetarian diet and do quite well. For that matter, it is a healthy diet. Vegetarians have a lesser incidence of heart disease. However, meat is the best food source for iron and vitamin B-12. Unless a vegetarian diet includes foods that provide enough of those two nutrients, anemia can develop.

Premenopausal women need 18 mg of iron a day, and postmenopausal women, 8. Beans, potatoes, dried fruits, spinach, nuts, fortified bread and fortified cereal can supply iron. Two-thirds of a cup of raisins has between 1.8 and 2.5 mg. Plant foods don’t ordinarily have any vitamin B-12, but dairy products and fortified foods can provide the daily requirement.

Discovering if your anemia is due to a lack of iron or B-12 is relatively easy to accomplish with a few lab tests.

Your diet might not be the problem. There are many other possibilities. Blood loss through unrecognized bleeding from the intestinal tract is a routine anemia cause. That too is easily identified.

If you do lack either iron or B-12, the cure is readily available in capsule or tablet form. Before reaching for a capsule or tablet, make sure such a deficiency is the problem.

DEAR DR. DONOHUE: I am sending a lot of hard questions your way. Many people have backaches, and doctors always order X-rays, physical therapy and medicines. Isn’t it possible that backaches are caused by internal things like liver trouble? I am 85 and have had back trouble for years. I have seen many doctors myself. Could constipation be the cause? My back seems to hurt when I am constipated, and the pain disappears when I am not. – F.R.

ANSWER: Most back pain can be traced to something gone wrong with anatomical structures in the back – muscles, backbones, discs or spinal nerves. However, that still leaves a considerable number of back-pain patients whose trouble lies distant from the back and its structures.

Ulcers, stomach cancer, colon cancer, gallbladder disease, pancreas inflammation, bulges of the aorta wall, kidney stones and uterine fibroids are but a sample of the things that can makes themselves known through back pain.

Constipation? I don’t know. I have no reason to doubt your observations – at least as far as your body reacts – but I am reluctant to make them applicable to all people.

DEAR DR. DONOHUE: My wife has dementia, according to the family doctor. He suggests that she take the pill Aricept to bring her memory back or to slow down its loss. Has it been proven to work? – A.H.

ANSWER: Dementia is impairment of thought functions and memory. The most common cause of dementia is Alzheimer’s disease.

Aricept is an Alzheimer’s drug. It slows the breakdown of a brain chemical called acetylcholine. That chemical is essential to the transfer of information from one brain cell to another.

It has improved mental function for some users, but not for all, and it might slow down the deterioration of mental function, but it is not a miracle drug. A trial is something that might prove useful for your wife.

Namenda is a newer Alzheimer’s drug, and it works by blocking the overproduction of another brain chemical, glutamate. Too much glutamate damages brain cells. Aricept and Namenda can be combined.

DEAR DR. DONOHUE: My 12-year-old son has asthma. He is under good care and seldom has an asthma attack. Can he play sports? Do children usually outgrow asthma? – G.H.

ANSWER: Children with well-controlled asthma are usually allowed to play any sport they desire. I can’t answer for your son. You have to get the word from his own doctor.

Many childhood asthmatics are no longer bothered by asthma when they reach adulthood. However, as many as 15 percent continue to have asthma attacks throughout life. Predictors of persistence include an age of onset at 6 or younger, a family with many asthmatics, and evidence of an immune system that is on the blink, one sign of which is a condition like eczema.

The asthma pamphlet furnishes answers to most asthma questions. To obtain a copy, write to: Dr. Donohue – No. 602, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.50 U.S/$6.50 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.