The purpose of this diet is to try and maintain a balance of electrolytes, minerals, and fluid in patients on dialysis. The special diet is important because dialysis alone does not effectively eliminate ALL waste products. These waste products can also accumulate between dialysis treatments. Most dialysis patients urinate very little or not at all, and therefore fluid restriction between treatments is very important.

Without urination, fluid will accumulate and result in volume overload with excess fluid in the heart, lungs and ankles. Patients on dialysis need a high protein intake to maintain adequate nutrition. Patients can become malnourished on dialysis and poor nutrition can often predict poor outcomes.

The diet will help dialysis patients feel as good as possible.

Protein -- The amount of protein allowed in the dialysis diet is determined by checking the amount of protein (and protein waste byproducts) in the person’s blood, as well checking the urea clearances before and after dialysis. This is usually monitored on a monthly basis. Laboratory tests may include chem-20, creatinine, albumin, and pre and post dialysis blood urea nitrogen.

Dialysis patients need to maintain a high protein intake to maintain good health and avoid becoming malnourished. Patients on peritoneal dialysis need even higher protein intake as a large amount of protein can be lost in the peritoneal fluid which is discarded.

Many dialysis patients have poor appetites and find it difficult to maintain an adequate protein intake. These patients are often given dietary supplements or agents to improve their appetites, such as Megace. Special dietary supplements are needed for dialysis patients with the correct amount of protein, electrolytes and minerals. These should be recommended only by the dietitian or physician. Patients should not take supplements on their own without consulting the dialysis physician.

Sodium -- Most patients need to control the sodium (salt) content in their diet. This helps in maintaining fluid balance in the body to avoid fluid retention and elevated blood pressure.

Potassium -- The daily intake of potassium is also controlled. This helps prevent hyperkalemia (a high level of potassium), a common problem for people on dialysis. Potassium is also added to the dialysis solution and the amount of potassium added is determined by measuring the potassium in the blood usually on a monthly basis.

Phosphorus -- The mineral phosphorus is also controlled in this particular diet. Phosphorus is not effectively removed by dialysis treatments and needs to monitored at least monthly. Patients need to reduce the intake of dairy products and other foods high in phosphorus. Patients are given medications to bind the phosphorus in the bowel. They are usually prescribed calcium supplements which bind the phosphorus in food. It is important to take these calcium tablets (phosphate binders) with meals.

If a patient has a high level of calcium in the blood they may be given a non-calcium phosphorus binder, such as Renagel. The amount of binders that need to be taken by each patient is determined by their blood levels of phosphorus and their intake of phosphorus containing foods in the diet. High phosphorus levels can be dangerous as they lead to bone disease and can bind to calcium in the blood forming calcium phosphorus precipitates which can lodge in the heart and blood vessels.

Fluids -- During renal failure, the amount of urine the body produces is decreased. The urine output usually stops completely once patients have been on dialysis for more than 6 months. Patients on peritoneal dialysis usually retain their urine output for a longer period of time and have less restriction on fluid intake.

The recommended daily amount of fluid is based on the amount of urine produced in a 24-hour period and on the amount of weight that is gained between dialysis treatments. Other considerations are the amount of fluid retention present, the level of dietary sodium, and the presence or absence of congestive heart failure.

Patients on peritoneal dialysis usually have less restriction on their fluid, sodium and potassium intake as they have dialysis treatments every day. The intake of these substances needs to be individualized in these patients.

Other -- People with renal disease are more prone to cardiovascular (heart) disease and they often need to follow a low cholesterol diet. Diabetics also need to follow a low carbohydrate diet. The daily calorie intake needs to be adequate to maintain the person’s nutritional status at an optimal level and to prevent the breakdown of body tissue. The person’s weight and protein status should be monitored regularly.

Vitamin supplementation is usually needed. The requirements for the fat-soluble vitamins (A, D, E, and K) are usually met by the diet. Vitamin D is usually supplemented depending on the calcium, phosphorus and parathyroid hormone levels. Vitamin D is usually given intravenously during the dialysis treatment. The intake of water-soluble vitamins is often inadequate, as several good food sources of water-soluble vitamins are restricted on this diet. There is also loss of water-soluble vitamins during the dialysis treatments. All dialysis patients should receive vitamin supplementation of water soluble vitamins.

The minerals that are also monitored include calcium and iron. The recommended supplementation of daily calcium depends on the patients blood calcium levels. Calcium is also given in the dialysis solution and is adjusted according to the blood calcium levels. Iron supplementation is based on iron studies that are usually monitored every 3 months. Most dialysis patients are iron deficient and receive intravenous iron during dialysis treatments.

Note: not all people on dialysis need dietary supplements.

SUPPORT GROUPS
The Kidney Foundation has chapters in most states and is an excellent resource for educational materials and programs for people on dialysis and their families.

Most dialysis centers have registered dietitians who work with patients and physicians to ensure that the patients are educated about the importance of their diet while on dialysis. Renal dietitians are also a resource for nutrition information specific to kidney disease and dialysis.