- 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.
More answers
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- Water softeners: How much sodium do they add?
- Fiber supplements: Are they safe to take every day?
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- Canola oil: Does it contain toxins?
- Dietary supplements vs. food: Which is better?
- E. coli: How can I tell if food is contaminated?
- Roasting nuts: Lower fat by roasting in the shell?
- Yerba mate: Is it safe to drink?
- Water after meals: Does it disturb digestion?
- Ground flaxseed: Better than whole?
- Diverticulitis diet: Should I avoid nuts and seeds?
- Monosodium glutamate (MSG): Is it harmful?
- Canned pumpkin: Better than fresh?
- Smart Balance: Are cholesterol-lowering products safe for everyone?
- Vitamin water: Better than plain water?
- Diet soda: Is it bad for you?
- Microwave popcorn: Is it linked to lung disease?
- Too skinny? How to add pounds safely
- Sea salt vs. table salt: Which is better?
- Caffeine: Is it dehydrating or not?
- Prenatal vitamins: OK for women who aren't pregnant?
- Grape juice: Same heart benefits as wine?
- Diverticulitis diet: What should I eat after an attack?
- Lentils: How do I cook with them?
- see all
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Question
Calcium supplements: Should they be taken with meals?
Should calcium supplements be taken with meals? At a certain time of day?
Answer
from Katherine Zeratsky, R.D., L.D.
Whether calcium supplements should be taken with meals depends on what the supplements contain.
If your calcium supplements contain calcium carbonate, take them with meals. Stomach acid enhances absorption of calcium carbonate. If your calcium supplements contain calcium citrate, you can take them with meals or on an empty stomach. Unsure? Check the product label.
You can take calcium supplements at any time of day. However, it's important to note that calcium is absorbed most efficiently when it's taken in amounts of 500 milligrams (mg) or less. If you take 1,000 mg of calcium a day, split it into two or more doses over the course of the day.
It's also important to consider other medications. Because calcium supplements can impair the absorption of some medications — including certain antibiotics and blood pressure drugs — you may need to take your calcium supplements separately. Ask your doctor or pharmacist about possible interactions between calcium supplements and other medications you're taking.
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