A new report on the quality of potassium supplements from ConsumerLab.com, White Plains, NY, found that each product selected for review contained the claimed amount of this essential mineral, did not exceed contamination limits for lead, and, if a pill, was able to properly break apart.

The cost to obtain 99 mg of potassium, a common serving size, varied from 1 cent to 34 cents although those costing the most provided magnesium as well as potassium.

Potassium supplements are used to treat or prevent potassium deficiency and are commonly taken by people on diuretic drugs that treat high blood pressure but cause potassium loss. Potassium deficiency can cause muscle weakness, irregular heartbeat, listlessness, mood change, nausea and vomiting. Potassium may also help lower blood pressure in people who consume high amounts of sodium. Sales of potassium supplements in the U.S. were estimated at $82 million in 2009, according to Nutrition Business Journal.

“We are glad that the findings for this group of potassium products were positive, but consumers should keep in mind that even straightforward supplements like potassium don’t always deliver what they promise,” said Tod Cooperman, MD, ConsumerLab.com’s president. “The supplement product you choose may affect your well-being, particularly if you rely on it to prevent or treat a deficiency.”