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. 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. 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 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 bodyвs 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. 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. 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.
Potassium and magnesium balance are frequently altered by common pathological conditions. Isolated disturbances of potassium balance do not produce secondary abnormalities in magnesium homeostasis. In contrast, primary disturbances in magnesium balance, particularly magnesium depletion, produce secondary potassium depletion. This appears to result from an inability of the cell to maintain the normally high intracellular concentration of potassium, perhaps as a result of an increase in membrane permeability to potassium and/or inhibition of Na+-K-ATPase. As a result, the cells lose potassium, which is excreted in the urine. Repletion of cell potassium requires correction of the magnesium deficit.
Are such magnesium dependent alterations in potassium balance of any clinical significance? Within the context of electrolyte disturbances, magnesium replacement is often necessary before hypokalemia and potassium depletion can be satisfactorily corrected with potassium supplements. The hyponatremia often seen with chronic diuretic usage may also be related to depleted intracellular potassium stores. In a small group of patients with chronic congestive heart failure, magnesium replacement alone was sufficient to correct this hyponatremia. Finally, magnesium and potassium depletion may play an important role in the development of cardiac arrhythmias in certain select groups of patients, such as those with overt ischemic heart disease. The frequency of magnesium depletion in some clinical disease states warrants renewed interest in the relationship between magnesium and potassium homeostasis.