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Katherine Zeratsky, R.D., L.D.read biographyclose window
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 (31)
- Phenylalanine in diet soda: Is it harmful?
- Water softeners: How much sodium do they add?
- Diet soda: Is it bad for you?
- see all in Nutrition basics
Healthy diets (11)
- Canola oil: Does it contain toxins?
- Butter vs. margarine: Which is better for my heart?
- Detox diets: Do they work?
- see all in Healthy diets
Healthy cooking (7)
- When the heat is on, which oil should you use?
- Moldy cheese: Is it OK to eat?
- Food poisoning: How long can you safely keep leftovers?
- see all in Healthy cooking
Healthy menus and shopping strategies (8)
- White whole-wheat bread: Is it nutritious?
- Sodium nitrate in meat: Heart disease risk factor?
- Brominated vegetable oil: Why is BVO in my drink?
- see all in Healthy menus and shopping strategies
Nutritional supplements (18)
- What is wheatgrass — And why is it in my drink?
- Prenatal vitamins: OK for women who aren't pregnant?
- Too much vitamin C: Harmful?
- see all in Nutritional supplements
Calcium supplements: When should they be taken?
When should I take calcium supplements? Does the timing matter?
from Katherine Zeratsky, R.D., L.D.
Yes. Three factors determine when you should take calcium supplements:
- The type of calcium. Check the label to find out what kind of calcium a supplement contains. If the supplement contains calcium citrate, you can take it with or without food. If the supplement contains calcium carbonate, take it with food. Stomach acid produced while eating helps the absorption of calcium carbonate.
- The daily dose. Calcium is absorbed most efficiently when it's taken in amounts of 500 milligrams (mg) or less at one time. So if you take 1,000 mg of calcium a day, split it into two or more doses over the day.
- If you take prescriptions. Calcium supplements can interact with many prescription medicines, including antibiotics, bisphosphonates and high blood pressure medications. Ask your doctor or pharmacist about possible interactions between calcium supplements and your medications.
It's also a good idea to take your calcium supplements at a different time from your multivitamin or an iron-rich meal. Calcium may not be absorbed as well if it's taken at the same time as iron, zinc or magnesium.
If you still aren't sure about the best time to take calcium supplements, check with your doctor or pharmacist for guidance.Next question
Fiber supplements: Safe to take every day?
- Straub D. Calcium supplementation in clinical practice: A review of forms, doses, and indications. Nutrition in Clinical Practice. 2007;22:286.
- Hamrick I, et al. Vitamin and mineral supplements. Primary Care: Clinics in Office Practice. 2008;35:729.
- Calcium. Natural Medicines Comprehensive Database. http://www.naturaldatabase.com. Accessed July 16, 2012.
- Dietary supplement fact sheet: Calcium. Office of Dietary Supplements. http://ods.od.nih.gov/factsheets/calcium.asp. Accessed July 16, 2012.
- Rosen HN. Calcium and vitamin D supplementation in osteoporosis. http://www.uptodate.com/home/index.html. Accessed July 16, 2012.