Potassium and Kidneys
Potassium is an essential mineral for healthy functioning cells, tissues and organs in the human body. Potassium is crucial to heart function and plays a key role in muscle contraction. When our bodies have excess potassium, healthy kidneys dispose of 90% of what is not needed. As you lose kidney function, less potassium is removed and blood levels increase. When your kidneys are unable to rid your body of excess potassium, your dietitian may advise that you monitor and limit your potassium intake.
The amount of potassium you should consume depends on your remaining kidney function and dialysis therapy. Most people on hemodialysis need 2,000-3,000 mg of potassium each day and should have a blood potassium level of 3.5-6.0 milliequivalents per liter (mEq/L). Just about all foods contain potassium, so our dietitians suggest distributing your daily potassium intake as follows:
- 900 mg for fruits/vegetables (about four to six servings)
- 900 mg for meats
- 900 mg for milk and grains
What you can do if your potassium is too high:
- Stop using potassium based salt substitutes.
- Check labels on low sodium products to be sure potassium chloride is not on the ingredient list.
- Check the nutrition facts label to see if potassium content is listed. Compare and choose the lowest potassium products.
- Learn which fruits and vegetables are highest in potassium. Eat these foods less frequently and in smaller portions or replace with lower potassium choices. Some high potassium foods include avocado, banana, cantaloupe, kiwi, oranges, papaya, beans, potatoes, tomatoes, spinach, sweet potato, winter squash and vegetable juice.
- Limit milk and yogurt, as both are very high in potassium.
- Ask your dietitian for a list of foods that contain potassium.
Reading Food Labels: Looking for Potassium Content of Foods
Most people on hemodialysis are advised to limit their potassium intake to 2,000-3,000 milligrams (mg) per day. We know that potatoes, oranges, milk and salt substitutes have high potassium contents, but we need to rely on the food Nutrition Facts Label for information on other foods. Some, but not all foods include potassium on the label. It is helpful to know what to look for to make it easier to read the food label.
Food labels are not required to report potassium levels, but many do. They may state the amount in milligrams (mg) or % DV (the percentage of the daily value reference amount).
The daily value percentage for potassium listed on Food Nutrition Facts labels is based on a diet allowing for 3,500 mg of potassium each day. This food label listing 10% of the daily value for potassium contains about 350 mg potassium. It is important to remember that if you are undergoing hemodialysis, your recommended daily intake is between 2,000-3,000 mg and you will need to make adjustments accordingly when reading nutrition labels.
If the potassium content or % daily value is not listed, check the ingredient list for these potassium additives:
- Potassium citrate
- Potassium gluconate
- Potassium chloride
- Potassium nitrate
- Potassium caseinate