Potassium, Phosphorus and the Dialysis Diet

By DaVita® renal dietitian Helen Dorrough, RD

Potassium is a mineral found in most of the foods we eat and is necessary in the diet because it helps with muscle movement and keeping the nervous system healthy. It also helps balance the amount of water in the body. The amount of potassium in the blood is controlled by the kidneys. For people with kidney disease, potassium levels can build up to high levels in the blood. This is called hyperkalemia and can be dangerous for the heart.

Phosphorus is also a mineral we get from eating certain foods. Phosphorus helps build strong bones and teeth. It also helps convert food into energy and helps with metabolism. Kidneys normally release extra phosphorus into the urine; however, kidney disease can prevent the body from getting rid of buildup that causes problems for the bones and heart.

Limiting potassium and phosphorus in the hemodialysis diet

Potassium-rich foods are limited for those on hemodialysis because potassium builds up between dialysis treatments and can cause problems such as weakness, muscle cramps, tiredness, irregular heartbeat and even heart attack. Potassium is found mostly in fruits, vegetables and dairy products. Certain fruits and vegetables are high in potassium and others are lower. However, eating a large amount of a low-potassium food can cause potassium to add up to dangerous levels. Be aware that most foods contain some potassium—meat, poultry, bread, pasta. Butter, margarine and oils are the only foods that are potassium-free.