Pill Users: Watch Vitamin C Intake


Question: You’ve written about estrogen interactions with grapefruit and with alcohol, but what about vitamins? Also, should women on the birth control pill not eat grapefruit at all, or just within a couple of hours of taking the pill?

I am unclear about alcohol: Will a glass of wine with dinner decrease the effectiveness of my Triphasil if I take the pill at 10 p.m.?

Lately I think that vitamin C is making me sick. Now it makes me feel nauseated and makes my breasts tender. Could this be due to an interaction with the pill?


Answer: Estrogen levels in women taking birth control pills or undergoing estrogen replacement therapy may be increased by high doses of vitamin C. Researchers have found that 1,000 milligrams of vitamin C can have a significant effect. Your symptoms of nausea and breast tenderness could indicate high levels of circulating estrogen.

Alcohol (wine, beer, mixed drinks) and grapefruit boost estrogen levels as well. The impact of grapefruit on drug metabolism is long-lasting, perhaps into the following day.

An occasional glass of wine or half a grapefruit should not be a problem. If you drink grapefruit juice or alcohol daily, you may elevate your estrogen levels more than you realize. Researchers are concerned that prolonged exposure to high levels of estrogen may increase a woman’s risk of breast cancer.

Many drugs (antibiotics, anticonvulsants, TB medicine, etc.) reduce the effectiveness of the pill. Alcohol does not.

Q: My husband has heart disease. He has been taking atenolol for years. Recently he has been skipping doses several times a week. I can’t help but think this is doing some harm. Is that true?

A: Your husband is putting himself at risk. Stopping a beta blocker such as atenolol suddenly could trigger angina or even a heart attack. Skipping a dose or two could be hazardous. Please urge him to take this medicine seriously.

Q: Do you know of any company that makes an 81-milligram aspirin tablet, enteric-coated, that is free of dyes? Now that I’m 50, my nurse practitioner has suggested I take one of these each day, but the ones I’ve seen are red or yellow.

Could I just cut a regular aspirin into four fairly evenly divided pieces? If the sizes of the pieces are not all the same, does this matter?

A: We too were unable to locate an enteric-coated 81-milligram aspirin without artificial colors. Your idea of cutting an aspirin into quarters and taking one-fourth each day with food is reasonable. A pill cutter could increase your precision, but studies have shown cardiovascular benefits at doses ranging from as low as 30 milligrams up to an entire regular aspirin tablet (325 milligrams).

* Joe Graedon is a pharmacologist. Teresa Graedon holds a doctorate in medical anthropology and is a nutrition expert. Send questions to them at People’s Pharmacy, c/o King Features Syndicate, 235 E. 45th St., New York, NY 10017, or e-mail them via their Web site: