- With Mayo Clinic nutritionist
Katherine Zeratsky, R.D., L.D.
read biographyclose windowBiography of
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.
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Question
Calcium supplements: When should they be taken?
When should I take calcium supplements? Does the timing matter?
Answer
from Katherine Zeratsky, R.D., L.D.
In general, you can take calcium supplements at any time during the day. But there are several factors to consider that may affect the timing of taking calcium supplements, including how much you take, other medications you may take and the form of calcium supplement you take (check the product label).
- Dosage. Calcium is absorbed most efficiently when it's taken in amounts of 500 or 600 milligrams (mg) or less at one time. If you take 1,000 mg of calcium a day, split it into two or more doses over the course of the day.
- Medications. Calcium supplements can interact with many different prescription medications, including antibiotics, bisphosphonates and high blood pressure medications. You may need to take calcium supplements several hours before or after taking your medications. Ask your doctor or pharmacist about possible interactions between calcium supplements and medications you're taking to make sure you time the doses correctly.
- Calcium carbonate. If your calcium supplements contain calcium carbonate, take them with food. Stomach acid produced while eating helps the absorption of calcium carbonate.
- Calcium citrate. If your calcium supplements contain calcium citrate, you can take them with or without food.
If you still aren't sure about the best time to take calcium supplements, check with your doctor or pharmacist for guidance.
- 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 26, 2010.
- Dietary supplement fact sheet: Calcium. Office of Dietary Supplements. http://ods.od.nih.gov/factsheets/calcium.asp. Accessed July 26, 2010.
- Zeratsky KA (expert opinion). Mayo Clinic, Rochester, Minn. Aug. 17, 2010.
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