- 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 (24)
- Multigrain vs. whole grain: Which is healthier?
- Healthy chocolate — Dream or reality?
- Yerba mate: Is it safe to drink?
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Healthy diets (9)
- Water after meals: Does it disturb digestion?
- Diverticulitis diet: Should I avoid nuts and seeds?
- Diverticulitis diet: Can certain foods trigger an attack?
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Healthy cooking (8)
- 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)
- 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
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Nutritional supplements (14)
- Vitamin C: Can too much be harmful?
- Chocolate: Does it impair calcium absorption?
- Percent Daily Value: What does it mean?
- see all in Nutritional supplements
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Question
Calcium supplements: Which type is best?
How do I know which calcium supplements provide the most calcium? There are so many different kinds — carbonate, citrate, lactate, gluconate.
Answer
from Katherine Zeratsky, R.D., L.D.
The key factor to consider when buying calcium supplements is the amount of elemental calcium the supplements contain. The term "elemental calcium" refers to the amount of calcium in a supplement that's available for your body to absorb. Don't be deceived by the total weight of each tablet, which is simply the weight of the calcium plus whatever it's bound to — such as carbonate, citrate, lactate or gluconate.
If the amount of elemental calcium isn't clearly listed on the label, check the Nutrition Facts label. The amount of elemental calcium will be listed in milligrams (mg) according to "serving size" — generally one or two tablets. The Nutrition Facts label also lists the Percent Daily Value (% Daily Value), which indicates how much one serving provides toward the average daily recommended amount of a given nutrient for most people. For calcium, the % Daily Value is 1,000 mg of elemental calcium. Remember, however, your needs for calcium may vary according to recommendations from your doctor or dietitian.
When choosing calcium supplements, it's also helpful to note how much calcium is in the serving size listed on the label. This will help you determine the number of tablets you must take to meet your individual needs for calcium. Also look for "USP" or "CL" on the label. Supplements that bear The United States Pharmacopeia (USP) or ConsumerLab (CL) abbreviations meet voluntary industry standards for quality, purity, and tablet disintegration or dissolution.
Next questionCalcium supplements: Do men need them too?
- Dietary supplement fact sheet: Calcium. Office of Dietary Supplements. http://ods.od.nih.gov/factsheets/calcium.asp. Accessed Aug. 26, 2008.
- About USP — An overview. U.S. Pharmacopeia. http://www.usp.org/aboutUSP. Accessed Aug. 26, 2008.
- About ConsumerLab.com. ConsumerLab.com. http://www.consumerlab.com/aboutcl.asp. Accessed Aug. 28, 2008.
