Phosphorus and the kidney diet

Phosphorus is a mineral that is vital for good health, since it is needed by every cell in your body for normal function. It is a major component of your bones and teeth and also assists your body in:

• secreting hormones
• storing and producing energy
• utilizing B vitamins
• controlling pH balance
• delivering oxygen to your tissues
• supporting the health and growth of connective tissues and organs

When your kidneys are not working as they should, they often cannot remove excess phosphorus from your bloodstream, and so phosphorus can build to unhealthy levels.

Excess phosphorus can cause calcium to leach from your bones so that over time they may weaken and break. And, if you have high levels of both phosphorus and calcium, damaging calcium deposits can form in soft tissues including your heart, lungs, eyes and blood vessels. That’s why, if you are diagnosed with chronic kidney disease (CKD), you’ll need to monitor and control the levels of both phosphorus and calcium in your body.

Generally, the recommended daily amount of phosphorus for adults is between 800 mg and 1,200 mg. Many foods provide phosphorus, so it is easy to get enough for good health. Very few people suffer from phosphorus levels that are too low. This is especially true now that Americans are eating more canned and bottled drinks and prepared foods. Since food additives often contain phosphorus, the rise in consumption of prepared foods has contributed to an accompanying rise in phosphorus in the American diet. In fact, in the last 20 years, Americans’ consumption of this mineral has risen 10 to 15 percent.

If you are on dialysis, your health care provider will do monthly laboratory tests to check your blood phosphorus level. A healthy range is considered to be 3.5 to 5.5 mg/dL.

The role of dialysis in phosphorus control

Dialysis will remove some phosphorus from your bloodstream, but it is important to realize that you must also keep your phosphorus levels in check between dialysis treatments. One important step in managing phosphorus is to eat a diet that helps limit your intake of the mineral. Your renal dietitian can provide lists of what foods to include in your food plan and what foods should be limited or avoided altogether.

When your goal is to limit your phosphorus intake, you cannot rely on reading food nutrition labels alone to alert you to foods that contain it, since food labels are not required by law to list the mineral. If you check the ingredients and see variations of the word phosphorus – including pyrophosphate, polyphosphates, phosphoric acid, calcium phosphate and sodium aluminum phosphate – then you will know the food is high in phosphorus and should be avoided.

In many cases, people with kidney disease will be prescribed phosphorus binders to assist in controlling phosphorus in the body. A phosphorus (or phosphate) binder works to absorb (bind) phosphorus in your stomach rather than allowing it to pass into your blood. The mineral is then eliminated in the stool.

If your health care provider prescribes phosphate binders, you will also be instructed on how and when to take them. Typically, they are taken right before or after eating meals or snacks.

Foods high in phosphorus

To avoid consuming too much phosphorus, your dietitian may recommend that you avoid or limit these high-phosphorus foods and beverages:

• dairy, including milk, drinks made with milk, yogurt, cheese, cottage cheese, pudding and ice cream
• pork
• hamburger
• chicken
• beef liver, chicken liver and other organ meats
• processed meats
• oysters, tuna, lobster and sardines
• dried beans and peas, such as lentils, split peas, lima beans, baked beans, kidney beans, black beans, chick peas and garbanzo beans
• rice, corn, potatoes and white bread
• broccoli, peas and avocado
• whole grain products, such as whole wheat bread and shredded wheat cereals
• nuts and seeds
• pizza
• colas
• cocoa and other chocolate drinks
• ale and beer
• canned iced teas

Eat this, not that

You can avoid high-phosphorus foods and still enjoy a satisfying meal plan. The chart below provides some tips for making smart, low-phosphorus choices that are compatible with a kidney-friendly diet.