The goals of treating chronic kidney disease are to slow down the progression of the disease, and to ameliorate the symptoms of renal insufficiency. Regular monitoring of blood and urine gives your nephrologist the information she needs to advise you about dietary matters. Sticking to your nephrologist's or renal dietitian's advice can make you feel better as renal function declines.
Sodium
Hypertension and kidney disease go hand-in-hand because the kidneys are involved in the regulation of blood pressure. As kidney disease progresses, patients are often on four or five different blood pressure medications. In addition to medication, eating a low sodium diet helps to keep blood pressure down. Relying on spices instead of the salt or soy sauce to season food helps control hypertension, and prolong the life of the kidneys.
Potassium
Healthy kidneys regulate the amount of potassium in the blood. In turn, this promotes healthy functioning of the nervous system. As kidneys become damaged, they are less able to remove excess potassium from the blood. This is potentially fatal, because excess potassium causes nerves to misfire, resulting in irregular heartbeats. If serum potassium levels exceed 5.0 mg/dl, nephrologists often recommend a low potassium diet. Avoiding high potassium foods such as oranges, bananas, squash, legumes, avocados, dates and melons can prevent serious heart problems.
Phosphorus
Kidneys also become less able to remove excess phosphorus from the blood as kidney disease progresses. High levels of phosphorus in the blood begin to pull calcium from the bones, causing permanent weakness. Doctors try to prevent this from happening by prescribing phosphorus binders, which remove excess phosphorus. Avoiding high phosphorus foods such as beer, milk, cheese, legumes and chocolate is also helpful.
Protein
If you have very high urine protein, your nephrologist might suggest a low protein diet. While healthy kidneys prevent proteins from passing through the kidney filters into the urine, scarred or inflamed kidneys often are unable to prevent this from happening. Getting urine protein under control is important because it can eventually damage the kidneys. Low protein diets are not for everyone, so you should never embark on one without your nephrologist's advice. Such diets are never recommended for children or patients on hemodialysis, or people immediately approaching transplant.
Vitamins
Patients in the latter stages of kidney disease often find it next to impossible to get adequate nutrition, especially because so many fruits and vegetables are high in potassium or phosphorus. To get around this problem, nephrologists often prescribe renal vitamins which have no potassium or phosphorus. These vitamins also have no vitamin A, because patients usually have very high levels of this nutrient. Renal vitamins also contain an active form of vitamin D, because patients are usually unable to convert vitamin D in food to a form that their bodies can use.
References
- National Kidney Foundation: Potassium and Your CKD Diet
- National Institute for Diabetes and Digestive and Kidney Diseases: Eat Right to Feel Right on Dialysis
- National Kidney Foundation: Phosphorus and your CKD Diet
- DaVita: Sodium and Chronic Kidney Disease
- Davita: ABC's of Vitamins for Kidney Patients
