- 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 Food & Nutrition Center, 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, she 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 pediatrics at Mayo Clinic Rochester and nutrition education related to the physiology and recommended intakes for premature infants.
Other areas of interest include breast milk and formula safety, neonatal feeding, and nutrition for breast-feeding mothers.
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 (21)
- Diet soda: Is it bad for you?
- Water softeners: How much sodium do they add?
- Caffeine: Is it dehydrating or not?
- see all in Nutrition basics
Healthy diets (8)
- Diverticulitis diet: Can certain foods trigger an attack?
- Butter vs. margarine: Which is better for my heart?
- Canola oil: Does it contain toxins?
- see all in Healthy diets
Healthy cooking (10)
- Lentils: How do I cook with them?
- Food poisoning: How long can you safely keep leftovers?
- Canned pumpkin: Better than fresh?
- see all in Healthy cooking
Healthy menus and shopping strategies (6)
- Calories in sushi: What are the low-cal options?
- Vegetable juice: As good as whole vegetables?
- Buying beef? A guide to choosing the leanest cuts
- see all in Healthy menus and shopping strategies
Nutritional supplements (15)
- Vitamin water: Better than plain water?
- Ground flaxseed: Better than whole?
- Vitamin C: Can too much be harmful?
- see all in Nutritional supplements
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Question
Vitamin D toxicity: What if you get too much?
What is vitamin D toxicity, and should I worry about it since I take supplements?
Answer
from Katherine Zeratsky, R.D., L.D.
Vitamin D toxicity, also called hypervitaminosis D, is a potentially serious but treatable medical condition that occurs when you get too much vitamin D.
Vitamin D toxicity usually results from taking an excessive amount of vitamin D supplements — not from your diet or too much sun exposure. That's because your body produces only a limited amount of vitamin D from sun exposure, and even fortified foods don't contain large amounts of vitamin D. Although vitamin D toxicity is rare even among people who take supplements, you may be at greater risk if you have health problems, such as liver or kidney conditions, or if you take thiazide-type diuretics.
The main consequence of vitamin D toxicity is a buildup of calcium in your blood (hypercalcemia), causing symptoms such as:
- Nausea
- Vomiting
- Poor appetite
- Constipation
- Weakness
- Confusion
- Heart rhythm abnormalities
- Kidney stones
Treatment of vitamin D toxicity may include:
- Stopping vitamin D supplements
- Restricting calcium intake
- Medications
- Hydration with fluids
- Hospitalization in severe cases
Vitamin D is an essential nutrient. The Institute of Medicine recommends that children and adults up to age 50 get 200 international units (IU) of vitamin D daily. The recommendation for adults over age 50 is 400 to 600 IU daily. However, many health experts consider these recommendations to be too low. The American Academy of Pediatrics, for instance, now recommends that children and adolescents get 400 IU of vitamin D daily. Many experts now "unofficially" recommend that adults get as much as 1,000 to 2,000 IU of vitamin D daily. In addition, it's likely that the vitamin D guidelines will be revised upward.
Supplements can be a reasonable way to meet recommended levels — as long as you pay attention to how much you take. And be sure to tell your doctor about any supplements you take.
Next questionPrenatal vitamins: OK for women who aren't pregnant?
- Leu JP, et al. Vitamin D toxicity: Caveat emptor. Endocrine Practice. 2008;14:1188.
- Hemmelgarn M. Shedding light on vitamin D. American Journal of Nursing. 2009;109:19.
- Lee JH, et al. Vitamin D deficiency: An important, common, and easily treatable cardiovascular risk factor? Journal of the American College of Cardiology. 2008;52:1949.
- Dietary supplement fact sheet: Vitamin D. Office of Dietary Supplements. National Institutes of Health. http://ods.od.nih.gov/factsheets/vitamind.asp. Accessed June 2, 2009.
- Hathcock JN, et al. Risk assessment for vitamin D. American Journal of Clinical Nutrition. 2007;85:6.
- Brannon PM, et al. Overview of the conference "Vitamin D and Health in the 21st Century: An Update." American Journal of Clinical Nutrition. 2008;88(suppl):483S.
- Vitamin D. The Merck Manuals: The Manual for Healthcare Professionals. http://www.merck.com/mmpe/sec01/ch004/ch004k.html. Accessed May 21, 2009.
- Wagner CL, et al. Prevention of rickets and vitamin D deficiency in infants, children and adolescents. Pediatrics. 2008;122:1142.
- Hensrud DD (expert opinion). Mayo Clinic, Rochester, Minn. June 17, 2009.
