• image.alt
  • With Mayo Clinic emeritus hypertension specialist

    Sheldon G. Sheps, M.D.

    read biography

Mayo Clinic Health Manager

Get free personalized health guidance for you and your family.

Get Started

Free

E-Newsletter

Subscribe to receive the latest updates on health topics. About our newsletters

  • Housecall
  • Alzheimer's caregiving
  • Living with cancer

Question

Water softeners: How much sodium do they add?

I'm on a low-sodium diet, so I'm looking for ways to reduce my sodium intake. How much sodium does a water softener add to our tap water?

Answer

from Sheldon G. Sheps, M.D.

The amount of sodium a water softener adds to tap water depends on the "hardness" of your water. Hard water contains large amounts of calcium and magnesium — dissolved from the soil by rainwater. Some water-softening systems remove calcium and magnesium ions from hard water and replace them with sodium ions. The higher the concentration of calcium and magnesium, the more sodium needed to soften the water. Still, the amount of sodium in softened water that was originally very hard shouldn't be cause for concern.

The majority of sodium in the average diet comes from table salt and processed foods. The water from your tap may add a small amount of sodium to your diet, depending on the type of softener you use, but not a significant amount. As a general rule, an 8-ounce (236 milliliters) glass of softened tap water contains less than 12.5 milligrams of sodium. According to the Food and Drug Administration nutrient guidelines, this is in the very low-sodium range. The best way to decrease the sodium in your diet is by cutting back on table salt and processed foods.

If you're concerned about the amount of sodium in your softened water, there are some things you can do:

  • Switch to a type of water-purification system that doesn't replace magnesium and calcium with sodium.
  • Buy demineralized water for drinking and cooking.
  • Soften only the hot water and using unsoftened cold water for drinking and cooking.
Next question
Olive oil: What are the health benefits?
References
  1. Sodium in drinking water. U.S. Environmental Protection Agency. www.epa.gov/safewater/ccl/sodium.html. Accessed March 24, 2009.
  2. Yarows SA, et al. Sodium concentration of water from softeners. Archives of Internal Medicine. 1997;157:218.

AN00317

May 19, 2009

© 1998-2009 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. A single copy of these materials may be reprinted for noncommercial personal use only. "Mayo," "Mayo Clinic," "MayoClinic.com," "EmbodyHealth," "Reliable tools for healthier lives," "Enhance your life," and the triple-shield Mayo Clinic logo are trademarks of Mayo Foundation for Medical Education and Research.

Print Share Reprints

Text Size: smaller largerlarger