Dr. MJ Bazos MD, Patient Handout
Nutrition & Chronic Renal Insufficiency

What are the Kidneys?
The kidneys are the master chemists of the body. Normally, there are two of them, one on either side of the spine under the lower ribs. They are reddish brown in colour and shaped like kidney beans. Each kidney is about the size of your clenched fist.

What do the Kidneys Do?
Healthy kidneys do three essential things. They remove wastes from the blood via the urine and return the cleaned blood back to the body. They regulate the levels of water and different minerals needed by the body for good health. They produce hormones that control other body functions. Many other organs depend on the kidneys in order to work properly.

What is Chronic Renal Insufficiency (CRI)?
Chronic renal insufficiency (CRI) is another term for kidney failure. This means the kidneys are working at less than 50% of normal. CRI happens when kidney disease interferes with the kidneys' ability to remove wastes from the body. Although chronic renal insufficiency has many causes, diabetes and high blood pressure are common ones..

What symptoms may occur with CRI?
Usually, CRI starts slowly and progresses over a number of years. During the early stages, there may be no warning symptoms. Later, as the kidneys continue to fail, more waste products like urea build up in the blood (this condition is called uremia) and can make you feel sick.

Anemia can also occur. This is a reduced amount of red blood cells in the body and can make you feel very weak, tired and sometimes more sensitive to cold. Although people with CRI become anemic because their kidneys have stopped making erythropoietin (EPO), a hormone which helps make red blood cells, they may also have low levels of iron in the blood and may need to take iron supplements.

What are the Treatments for CRI?
In the early stages, the only treatment needed may be a change in diet, control of blood pressure and/or the use of some specific medications. When the kidneys are near the end of their function (less than 10% of their normal rate), either dialysis or transplantation is needed. This period is called end-stage renal disease or ESRD

How can Proper Nutrition Help?
When your kidneys can no longer do their job well, you have to control the kinds and amounts of food you eat. Together, you and your dietitian will make a daily eating plan which will:

Meet your nutritional needs
Cut down the workload on your kidneys
Help keep the kidney function that is left (before starting dialysis)
Control the build-up of food wastes
Reduce symptoms like fatigue, nausea, itching and bad taste in the mouth
Control the effects of high blood sugars if you have diabetes

Each person has different needs depending on their age, medical history and kidney function. Your dietitian will work with you to design an individual daily eating plan that's right for you. Together you can plan proper food choices to keep you feeling as well as possible, and to try to slow the loss of kidney function.

What are Healthy Food Choices?
The following are the foods and nutrients you will have to consider to help relieve symptoms, control blood pressure and maintain health. These are protein, sodium, potassium and phosphorus. If you have diabetes, it is also important to watch carbohydrates for better blood sugar control.

Protein builds, repairs and maintains your body tissues. It also helps your body fight infections and heal wounds. As your body breaks down protein foods, a waste called urea is formed. If this is not eliminated, too much urea in the blood may cause tiredness, nausea, headaches and a bad taste in your mouth. If you eat too little protein, you may lose muscle and weight, lack energy and have difficulty fighting infetions. Your daily eating plan will provide enough protein for your body while limiting the amount of urea formed. Foods like meat, fish, poultry, eggs, tofu and milk are high in protein.

Sodium affects your body fluids and blood pressure. You need to control your salt intake and avoid foods with a high sodium content. These include processed foods like "deli" meats, canned foods, convenience and "fast" foods, salty snacks and salty seasonings.

To improve the taste of unsalted food, you can use unsalted spices, herbs, vinegar and lemon.

Potassium is a mineral which helps your nerves and muscles work well. Some potassium is necessary for good health, but too much can be dangerous. If the potassium level in your blood is too high or too low, it can affect your heartbeat. A very high level can cause the heart to stop beating. You may not feel any warning symptoms. If necessary, your doctor and dietitian may recommend you adjust how much potassium you eat. Your dietitian will give you a list of how much potassium is found in various foods and help you make an eating plan. This will help you make wise food choices to keep your potassium level within a healthy range. Some high potassium foods are potatoes, squash, bananas, oranges, tomatoes, dried peas and beans.

Phosporus (Phosphate)
Phosphorus is a mineral which normally keeps your bones strong and healthy. However, too much phosphorus may cause itchy skin or painful joints. When the kidneys start to fail, your blood phosphate level will rise. Therefore, you may need to limit certain foods which contain even a moderate amount of phosphorus. These include milk, cheese and other milk products, and protein foods such as meat, fish and poultry. However, you still need some milk products and protein foods for overall good nutrition, so your dietitian will make sure you have enough of these in your daily eating plan.

Generally, foods with very high levels of phosphorus, such as seeds, nuts, dried peas, beans and processed bran cereals, are not included in your daily eating plan.

Your doctor may also prescribe phosphate binders. These medications bind with the phosphorus in your intestine. The bound phosphorus will pass in your stool. You need to take phosphate binders with the food that contains the phosphorus. Do not take phosphate binders at the same time as iron supplements.

What about Fluids?
Some people need to limit their fluids while others can drink any amount they wish. As kidney function decreases, the kidneys may not produce as much urine as before, and your body may become overloaded with fluid. This can cause swelling of the legs, hands and face, high blood pressure and shortness of breath. To relieve such symptoms, you may need to limit your fluids. Your dietitian will build your fluid allowance into your daily eating plan. Fluids include water, soup, juice, milk, popsicles and gelatin.

Are Vitamin Supplements necessary?
Normally, a well-balanced diet will supply you with enough vitamins to keep you in good health. With kidney problems, however, you may need additional vitamins. Vitamin supplements must be prescribed by your doctor in collaboration with your dietitian. This ensures that you get the right kind. Some over-the-counter vitamins may be harmful.

What about herbal remedies and “health foods”?
Before you take any kind of herbal remedy or "health food", discuss this with your dietitian and doctor. These substances may create serious problems for someone with kidney disease.