- With Mayo Clinic nutritionist
Katherine Zeratsky, R.D., L.D.
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Katherine Zeratsky, R.D., L.D.
Katherine Zeratsky, R.D., L.D.
As a specialty editor for the nutrition and healthy eating guide, Katherine Zeratsky helps you sort through the facts and figures, the fads and the hype to learn more about nutrition and diet.
A Marinette, Wis., native, Katherine is certified in dietetics by the state of Minnesota and the American Dietetic Association. She has been with Mayo Clinic since 1999.
She is active in nutrition-related curriculum and course development in wellness nutrition at Mayo Clinic in Rochester, Minn., and nutrition education related to weight management and practical applications of nutrition-related lifestyle changes.
Other areas of interest include food and nutrition for all life stages, active lifestyles and the culinary arts.
She graduated from the University of Wisconsin-Madison, served a dietetic internship at the University of Iowa Hospitals and Clinics, and worked as a registered dietitian and health risk counselor at ThedaCare of Appleton, Wis., before joining the Mayo Clinic staff.
Nutrition basics (29)
- Healthy chocolate — Dream or reality?
- Multigrain vs. whole grain: Which is healthier?
- Caffeine: Is it dehydrating or not?
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Healthy diets (10)
- Diverticulitis diet: Can certain foods trigger an attack?
- Butter vs. margarine: Which is better for my heart?
- Detox diets: Do they work?
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Healthy cooking (6)
- E. coli: How can I tell if food is contaminated?
- Canned pumpkin: Better than fresh?
- Food poisoning: How long can you safely keep leftovers?
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Healthy menus and shopping strategies (7)
- Vegetable juice: As good as whole vegetables?
- Calories in sushi: What are the low-cal options?
- Sodium nitrate in meat: Heart disease risk factor?
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Nutritional supplements (16)
- Vitamin water: Better than plain water?
- Ground flaxseed: Better than whole?
- Chocolate: Does it impair calcium absorption?
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Question
Too much vitamin C: Harmful?
Is it possible to take too much vitamin C?
Answer
from Katherine Zeratsky, R.D., L.D.
Vitamin C (ascorbic acid) is an essential nutrient. Still, it's possible to have too much vitamin C.
Vitamin C is a water-soluble vitamin that supports normal growth and development. Vitamin C also helps your body absorb iron. Because your body doesn't produce or store vitamin C, it's important to include vitamin C in your diet. For most people, a small glass of orange juice plus a serving of strawberries, chopped red pepper or broccoli provides enough vitamin C for the day. Any extra vitamin C will simply be flushed out of your body in your urine.
For adults, the recommended upper limit for vitamin C is 2,000 milligrams (mg) a day. Although too much dietary vitamin C is unlikely to be harmful, megadoses of vitamin C supplements may cause:
- Diarrhea
- Nausea
- Vomiting
- Heartburn
- Abdominal cramps
- Headache
- Insomnia
- Kidney stones
Remember, for most people, a healthy diet provides an adequate amount of vitamin C.
Next questionDo the benefits of vitamin C include improved mood?
- Vitamin C (ascorbic acid). Natural Medicines Comprehensive Database. http://www.naturaldatabase.com. Accessed Jan. 15, 2010.
- Vitamin C. American Dietetic Association. http://www.eatright.org/WorkArea/DownloadAsset.aspx?id=4294967699. Accessed Jan. 15, 2010.
- Pazirandeh S, et al. Overview of water-soluble vitamins. http://www.uptodate.com/home/index.html. Accessed Jan. 15, 2010.
- Dietary reference intakes: Vitamins. Institute of Medicine. http://www.iom.edu/Global/News%20Announcements/~/media/474B28C39EA34C43A60A6D42CCE07427.ashx. Accessed Jan. 15, 2010.
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