Potassium and Magnesium Supplements

When your potassium and magnesium levels are too high or too low, complications can arise. Supplements may be appropriate if you are deficient in either mineral. Deficiencies should be closely monitored and corrected under the care of a health care professional. Potassium and magnesium supplements may be harmful to certain people.

Your doctor should closely monitor your potassium and magnesium supplement use. (Image: kadmy/iStock/Getty Images)

Potassium and Magnesium in the Body

Potassium and magnesium are minerals and electrolytes that help regulate the function of the cells, tissue and organs. Most healthy people get enough potassium and magnesium from food to maintain appropriate levels in the body. According to the Food and Nutrition Board of the Institute of Medicine, the current adequate intake for potassium in adults is 4,700 milligrams daily, and the recommended dietary allowance for magnesium is 310 to 320 milligrams daily for women and 400 to 420 milligrams daily for men.

Possible Indications for Supplement Use

Potassium and magnesium are plentiful in fruits, vegetables, nuts, seeds and whole grains. Malabsorption, diarrhea, vomiting, excessive sweating, excessive sodium intake and use of certain medications may result in low potassium or magnesium levels. Symptoms of low potassium, also known as hypokalemia, include lack of energy, weakness, irregular heartbeat, muscle cramps and stomach disturbances. Symptoms of magnesium deficiency include nausea, vomiting, fatigue, numbness and tingling. In more severe cases, magnesium deficiency may lead to hypokalemia.

Magnesium and Potassium Balance

Magnesium deficiency often occurs alongside potassium deficiency because of conditions such as malabsorption, chronic alcoholism, Type 2 diabetes and cardiac disorders. Magnesium deficiency may lead to potassium deficiency because the body's cells are unable to maintain potassium levels inside the cells in the absence of adequate magnesium. It may be appropriate to correct hypokalemia with a supplement that provides both magnesium and potassium. A low potassium level will not lead to a magnesium deficiency.

Supplement Options

A health care professional may recommend a potassium or magnesium supplement or a potassium magnesium salt in the event of a deficiency. He may also recommend an electrolyte supplement that contains both nutrients in the event of too much perspiration and exposure to excessive heat. Both nutrients may also be found in a multivitamin, which is safe for use by most people, though these cannot contain more than 99 milligrams of potassium per serving.

Contraindications for Supplement Use

Certain people are at risk for developing high potassium levels, a potentially serious condition known as hyperkalemia. Older adults, people with reduced kidney function and people taking certain antibiotics, ACE inhibitors, potassium-sparing diuretics, and nonsteroidal anti-inflammatory drugs should not take potassium supplements. Even in healthy people, doses of greater than 18 grams at once may result in hyperkalemia. People with impaired kidney function should be cautious with magnesium supplement use. Too much supplemental magnesium may also cause gastrointestinal distress.