Are there any side effects from using vitamins C and E? Can they be harmful in high doses?
Both vitamins C and E are generally considered to be nontoxic and very safe. But there may be negative side effects, particularly at high doses.
There may also be interactions with other medications, supplements or even certain foods. If you are on medication for a chronic condition, it is always a good idea to check with your doctor before starting to take vitamins, minerals or other supplements. For example, vitamin E, in high doses, can cause bleeding in people who take blood-thinning drugs such as Coumadin (generic name, warfarin).
Vitamin E is a fat-soluble vitamin, meaning it is stored and transported throughout the body in the fat cells. But unlike other fat-soluble vitamins, such as A and D, vitamin E is not believed to have any significant adverse effects, even in very high doses.
The body of research evidence favoring the benefits of vitamin E continues to grow. It looks like it may have preventive effects against some forms of cancer and heart disease and may have beneficial effects for people with Alzheimer’s disease or diabetes. So vitamin E supplements may be worth taking, but I would not go hog-wild. The government’s “daily value” is 30 Iu (international units), but supplements are widely recommended at doses between 100 and 400 Iu per day.
Even though vitamin E appears to be very safe, I would suggest keeping your supplemental intake below 800 Iu per day. If you want to take higher doses for a specific medicinal use, do that under a doctor’s supervision.
Vitamin C is a water-soluble vitamin and any excess is excreted in the urine. The government’s daily value is 60 mg The so-called “megadoses” of vitamin C (greater than 1000 mg per day) may cause side effects such as nausea, diarrhea, kidney stones and others. Despite the popularity of vitamin C, the benefits of megadoses remains controversial.
One important reminder about nutritional supplements: Do not let the fact that you are taking vitamins lull you into a sense of false security regarding your diet. They are intended to be supplements, not substitutes, for a healthy diet. Always try to get the required nutrients from the food you eat and then take supplements as you feel is necessary.