- 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 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.
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Question
Colloidal silver: Is it safe?
My dad takes colloidal silver to maintain good health. It's true that he hasn't been sick in years, but I'd like to know if there are any good studies out there on the disease-fighting benefits of colloidal silver. Also, is it safe?
Answer
from Katherine Zeratsky, R.D., L.D.
Colloidal silver is not considered either safe or effective in any of the health claims manufacturers make. No studies to evaluate colloidal silver have been published in reputable medical journals. Thus, all the claims for health benefits are based on manufacturers' opinions and anecdotes.
The Food and Drug Administration does not consider colloidal silver safe or effective to treat any disease or condition. Taking colloidal silver could have serious side effects, such as:
- Argyria — an irreversible blue-gray discoloration of your skin, nails and gums
- Seizures and other neurological problems
- Kidney damage
- Indigestion
- Headaches
- Fatigue
- Skin irritation
- Drug interactions with penicillamine, quinolones, tetracycline and thyroxine medications
Whenever you're considering taking a new dietary supplement, two questions are key:
- Will this do what the manufacturer or advertiser claims?
- Is it safe for me?
Your physician is your best partner to help you answer such questions. However, in the case of colloidal silver, with no reliable evidence of a benefit and lots of potential risk, it's best to leave the silver for your jewelry!
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