Does Malnutrition Cause High Potassium?

Malnutrition and high serum potassium levels often occur together. Although there is a relationship between the two, malnutrition doesn't cause high potassium levels. Treating high serum potassium levels can cause malnutrition. Both are symptomatic of the problems that often arise with advanced kidney disease. Treating high potassium while preventing malnutrition is essential to successful management of end-stage kidney disease.

Potassium Regulation

Maintaining constant serum levels of potassium between 3.5 and 5.0 mEq/L is essential for normal nerve function. Healthy kidneys keep these levels constant by reabsorbing excess potassium from the blood and excreting it into the urine. The kidneys of patients with advanced disease are less able to perform this function, so serum potassium levels creep up.

High Potassium Levels

High plasma levels of potassium have negative effects on neuromuscular and cardiac function. High levels of potassium cause nerves to misfire, causing potentially fatal tachycardia and arrhythmias. Because high potassium levels often produce no symptoms, nephrologists try to prevent such effects by closely monitoring kidney patients and recommending low potassium diets to patients with potassium levels higher than 5.0 mEq/L.

Low-Potassium Diets

The National Kidney Foundation defines a high-potassium food as one that has more than 200 mg of potassium per serving. Many otherwise healthy foods, such as apricots, grapefruit juice, broccoli, oranges, mangoes, milk, lentils, potatoes, eggplant, cucumber and dates meet this definition and you will need to limit them to keep dietary potassium intake within the 2,000 to 3,000 mg range recommend by the NKF. Given that this diet is so restrictive, it is little wonder that malnutrition sets in.

Vitamin Supplements

Many nephrologists recommend vitamins for patients in the latter stages of kidney disease to prevent malnutrition. These vitamins are specially formulated to meet the needs of kidney patients. For example, renal vitamins contain a relatively small amount of vitamin C because more than 100 mg might cause oxalate deposits in the bones and soft tissues. These vitamins do not contain vitamin A because patients with advanced kidney disease often have elevated levels of this nutrient.