Low Potassium

INTRODUCTION — Potassium is a mineral that is found in many foods. It functions to keep the heart beating regularly, helps to maintain fluid balance, and allows the nerves and muscles to work properly. The kidneys are responsible for maintaining the optimal level of potassium in the blood. Some people who take certain medications or who have chronic kidney disease must limit the amount of potassium in their diet to keep their potassium level close to normal.
This topic will discuss the normal level of potassium, how it is measured in the blood, and how to eat a low potassium diet. A discussion of other treatments for chronic kidney disease is available separately.

WHY SHOULD I REDUCE POTASSIUM IN MY DIET? — Normally, the level of potassium in the body is balanced by taking in potassium from foods and excreting excess potassium in the urine. However, some people with chronic kidney disease cannot eliminate enough potassium in their urine because the kidneys are not functioning properly. As a result, the level of potassium in the blood can become elevated, causing a condition known as hyperkalemia (hyper=high, kal=potassium, emia=in the blood). Eating a low potassium diet can decrease the risk of developing hyperkalemia. The potassium level is measured by taking a small sample of blood from a vein. A typical normal range for potassium is 3.5 to 5 meq/L. A level greater than 6 meq/L is considered dangerous. A low level can be dangerous as well.
Hyperkalemia does not usually cause noticeable symptoms until the potassium level is very high. At this level, dangerous complications can develop, including an irregular heart rhythm or severe muscle weakness or paralysis.

HOW MUCH POTASSIUM DO I NEED? — Dietary guidelines for the general population recommend a diet that contains at least 4700 mg of potassium per day [1]. However, most people with chronic kidney disease are advised to consume less than 1500 to 2700 mg of potassium per day.
A registered dietitian or nutritionist can help to create a low potassium meal plan. An example of one such plan includes:

Fruit — One to three servings of low-potassium fruit per day

Vegetables — Two to three servings of low-potassium vegetables per day

Dairy and calcium rich foods — One to two servings of low-potassium choices per day

Meat and meat alternatives — Three to seven servings of low-potassium choices per day (approximately 15 percent of calories)

Grains — Four to seven servings of low-potassium grains per day

Almost all foods contain some potassium, so the key is to choose foods with a low potassium level, when possible.

Note the serving size when calculating the amount of potassium in a food; a large serving of a low potassium food may have more potassium than a small serving of a food with a high level of potassium.

Drain canned vegetables, fruits, and meats before serving.

Foods with high levels of potassium — The following foods have greater than 250 mg of potassium per serving and should be avoided or eaten in very small portions. A process of "leaching" can reduce the amount of potassium in some vegetables.
Whole grain breads and other products are often recommended to reduce the risk of heart disease and other conditions. However, whole grain products contain more potassium than refined grains, such as white flour, and are not recommended for people who require a low potassium diet. For these people, elevated potassium levels can quickly increase the risk of dangerous complications. Thus, the benefit of controlling the potassium level is often greater than the benefit of a diet that contains whole grains. However, careful monitoring of blood levels of potassium and an ongoing discussion with the health care team will allow for the most specific and optimal diet for an individual.

Unless noted, one serving is 1/2 cup (4 ounces).

Grains — Whole grain breads, wheat bran, granola and granola bars

Beverages — Sports drinks (gatorade, etc), instant breakfast mix, soy milk

Snack foods/sweets — Peanut butter (2 tablespoons), nuts or seeds (1 ounce), fig cookies, chocolate (1.5 to 2 ounces), molasses (1 tablespoon)

Fruits — Apricots, avocado (1/4 whole), bananas (1/2 whole), coconut, melon (cantaloupe and honeydew), kiwi, mango, nectarines, oranges, orange juice, papaya, pears (fresh), plantains, pomegranate (and juice), dried fruits (apricots (5 halves), dates (5), figs, prunes, raisins), prune juice, yams

Vegetables — Bamboo shoots, baked or refried beans, dried beans or peas, black beans, beets, broccoli (cooked), Brussels sprouts, cabbage (raw), carrots (raw), chard, greens (except kale), kohlrabi, olives, mushrooms (canned), potatoes (white and sweet), parsnips, pickles, pumpkin, rutabaga, sauerkraut, spinach (cooked), squash (acorn, butternut, hubbard), tomato, tomato sauce, tomato juice, and vegetable juice cocktail

Dairy products — Milk and milk products, buttermilk, yogurt

Proteins — (3 ounce serving) Clams, sardines, scallops, lobster, whitefish, salmon (and most other fish), ground beef, sirloin steak (and most other beef products), pinto beans, kidney beans, navy beans (and most other legumes, serving size is 1/2 cup)

Soups — Salt-free soups and low-sodium bouillon cubes, unsalted broth

Condiments — Lite salt or salt substitutes (avoid completely), imitation bacon bits; this is especially important because some people are told to follow a low salt diet and may be told to use salt substitutes.

Foods with low levels of potassium — The following foods have a low level of potassium (less than 250 mg on average). These low potassium foods can be consumed regularly, but care must be taken to consume appropriate portion sizes since potassium can quickly add up with large portion size. Unless noted, the serving size is 1/2 cup.

Grains — Foods prepared with white flour (eg, pasta, bread), white rice

Beverages — Non-dairy creamer, fruit punch, drink mixes (eg, Kool-Aid), tea (<2 cups or 16 ounces per day), coffee (<1 cup or 8 ounces per day)

Sweets — Angel or yellow cake, pies without chocolate or high potassium fruit, cookies without nuts or chocolate

Fruits — Apples (1), apple juice, applesauce, apricots (canned), blackberries, blueberries, cherries, cranberries, fruit cocktail (drained), grapes, grape juice, grapefruit (1/2), mandarin oranges, peaches (1/2 fresh or 1/2 c canned), pears (1 small fresh or 1/2 c canned), pineapple and juice, plums (1 whole), raspberries, strawberries, tangerine (1 whole), watermelon (1 cup)

Vegetables — Alfalfa sprouts, asparagus (6 spears), green or wax beans, cabbage (cooked), carrots (cooked), cauliflower, celery (1 stalk), corn (1/2 fresh ear or 1/2 cup), cucumber, eggplant, kale, lettuce, mushrooms (fresh), okra, onions, parsley, green peas, green peppers, radish, rhubarb, water chestnuts (canned, drained), watercress, spinach (raw, 1 cup), squash (yellow), zucchini

Proteins — chicken, turkey (3 ounces), tuna, eggs, baloney, shrimp, sunflower or pumpkin seeds (1 ounce)

Dairy products — Cheddar or swiss cheese (1 ounce), cottage cheese (1/2 cup)

Reducing potassium levels in vegetables — It is possible to remove some of the potassium in some vegetables with high potassium levels. Leaching is a process of soaking raw or frozen vegetables in water for at least two hours before cooking, allowing the process of diffusion to "pull" some of the potassium out of the food and into the water. These vegetables should be eaten infrequently because there is still a considerable amount of potassium present in the food after leaching.

Wash and then cut the raw vegetable into thin slices. Vegetables with a skin (eg, potatoes, carrots, beets, rutabagas) should be peeled before slicing.

Rinse the cut vegetables in warm water.

Soak the vegetables for at least two hours or overnight. Use a large amount of unsalted warm water (approximately 10 parts water to 1 part vegetables). If possible, change the water every four hours. Discard the soaking water.

Rinse the vegetables again with warm water.

Cook vegetables as desired, using a large amount of unsalted water (approximately 5 parts water to 1 part vegetables). Discard the cooking water.

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