Q: My inquiry is about vitamin C. My son is trying to sell me on taking 1,000 to 3,000 milligrams per day. He states that the body does not produce vitamin C. My thinking is if that is true, I don't need any great quantities of it.
I am 78 and in very good health. I eat a well-balanced diet with fruits and vegetables. I also engage in strenuous exercise. Do I need this extra vitamin C? -- R.W., West Harwich, Mass.
A: To the contrary, because your body does not make vitamin C, it is specifically required in the diet. This is also true for certain amino acids (the building blocks of proteins) and is the reason why vegetarians need to mix their sources of proteins.
The Federal Department of Agriculture has determined the average amount of vitamin C "needed" is about 60 milligrams, increasing to about 80 during pregnancy. Some also think the absorption of vitamin C decreases with age so older people should increase the amount they get.
Over the past 30 years a great deal has been said about the importance of taking much higher doses for optimal health. And some studies substantiate this general statement. It's thought that vitamin C helps keep us healthy because it is a beneficial antioxidant.
In deciding whether to take a vitamin supplement of any kind it's certainly important to assess the amount of vitamin in your diet. Vitamin C is primarily in citrus fruits and green leafy vegetables. For example, a stalk of broccoli contains about 150 milligrams and an orange about 60 milligrams.
As you can see, a good balanced diet, especially one that includes citrus fruits and leafy green vegetables, will easily provide the minimum amount recommended. However, if you want to increase the dosage to higher levels, it is easy and inexpensive to take a vitamin C supplement.
The question of how much is too much has not really been answered. Because your body gets rid of excess amounts, research indicates that a person can take thousands of milligrams every day for years without any detectable problems.
The one caveat to this is that high levels of vitamin C may interfere with certain medical blood tests, so be sure to discuss this with your doctor if you are going to have a blood test.
At this time I don't recommend that someone with a good, balanced diet take vitamin C supplements, but I suspect that future research will more solidly support this as a good idea. In the meantime I take it myself -- when I remember.
My decision is based on the growing evidence that in moderately larger doses it can have multiple beneficial effects; in moderate doses there does not appear to be negative side effects and it doesn't cost very much.
Update on breast cancer: Hearing more and more about breast cancer can be scary, especially if you don't think you can do anything about it. But you can.
You can increase early detection of breast cancer with self-exams and mammography screenings. But you can also decrease the risk of getting breast cancer in the first place.
A 16-year study shows us that you may have double the risk of getting breast cancer if you are very overweight. It can also be much harder to detect breast cancer in an overweight woman.
If you are overweight, please take more control of your life and try to lose some of the extra pounds. Through a gradual program of exercise and good eating habits, it is not hard to lose a pound a week. If you do, in a year you may cut your risk of breast cancer in half.
Dr. Allen Douma welcomes questions from readers. Although he cannot respond to each one individually, he will answer those of general interest in his column. Write to Dr. Douma in care of the Better Health & Medical Network, 585 Grove St., Herndon, Va. 20170.
This column is for informational and educational purposes only. It is not intended to provide medical advice or take the place of consultation with a doctor or other health-care provider.