DEAR DR. DONOHUE: I was given antibiotics for my ulcer. I was told that a germ is responsible for ulcers. How did I get it? How do I know if the germ has gone or when it comes back? – K.D.

ANSWER: The ulcer story has taken a strange twist. A bacterium, Helicobacter (HEEL-ee-coe-BACK-tur) pylori, has a hand in causing ulcers. How you or anyone else gets it is a question that cannot always be answered. Many people have it, and some of those who have it never come down with an ulcer – another inexplicable point.

At any rate, the bacterium can demolish the coat that protects the stomach and duodenum from the corrosive action of stomach acid and digestive juices. Those fluids then go to work on the stomach and duodenum and, in time, produce an ulcer.

Antibiotics have now become part of the standard therapy for ulcers. Drugs that control stomach acid are also given. Without antibiotic treatment, the chance for a recurrence is quite high.

There are many ways of detecting the presence of H pylori. One is the breath test. A patient ingests a substance called urea. It contains carbon atoms that emit low levels of radiation – not enough to cause any harm or any concern. If the H pylori germ is present, it gobbles urea and converts it into carbon dioxide. The radioactive carbon dioxide passes out the mouth and nose of the patient and can be easily detected. Not every ulcer patient needs to be tested for the presence of H pylori after undergoing treatment.

I don’t want to leave readers with the impression that H pylori is the sole cause of ulcers. Too much stomach acid is a factor. Suppressing acid production is as integral part of treatment as it has been in the past.

DEAR DR. DONOHUE: I have type 2 diabetes. My blood sugar has recently been on the high side, so I was given two oral diabetes medicines. When is insulin added to a program?

My recent fasting blood sugar was 110 mg/dL (6.1 mmol/L) – normal. However, something called hemoglobin A1C was high, at 9.2 (normal being up to 6). If I interpret this correctly, it indicates that my blood sugar is out of control. Will you please elaborate on the discrepancy here? – A.L.

ANSWER: Hemoglobin is a large protein inside red blood cells. It enables red blood cells to grab hold of oxygen and deliver it to all body locations.

When blood sugar rises, some of it sticks to hemoglobin – that’s hemoglobin A1C. The percent of hemoglobin to which sugar is attached gives a reliable indication of how well a person’s blood sugar was controlled during the past six to 12 weeks. The fasting blood sugar indicates what the level was only at the point in time when it was tested.

A good hemoglobin A1C reading is 6 or lower.

Are you testing your blood sugar at home? You should be. Having a record of what your daily blood sugars are gives the doctor important information for manipulating the dose and timing of diabetes medicine. That kind of information is important for someone like you.

Insulin is part of diabetes therapy for everyone with type 1 diabetes, the kind that used to be called juvenile diabetes. It is added to a program for type 2 diabetes (the old adult-onset diabetes) when diet, exercise and oral medicines cannot achieve good blood sugar control.

DEAR DR. DONOHUE: I don’t go outside much. I wonder if I am getting enough sunlight to make vitamin D. If I sit in front of a window with sunlight shining through, does that count as enough sun exposure for me to make vitamin D? – K.J.

ANSWER: Window glass blocks ultraviolet B rays. Those are the waves that turn a precursor compound found in skin into vitamin D. Sitting in front of a window won’t provide the kind of sun exposure you need. You can, however, open the window and let the light shine directly on you.

All you need for sufficient sun exposure in summertime is 15 minutes three times a week.

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.