When you have kidney disease, your kidneys cannot remove extra potassium in the right way, and too much potassium can stay in your blood. When you have too much potassium in your blood, it is called hyperkalemia, or high potassium. Having too much potassium in your blood can be dangerous

Why are CKD patients advised to restrict potassium in diet?

Potassium is an important mineral in the body that is needed for the proper functioning of muscles and nerves and to keep the heart beat regular.

Normally, the level of potassium in body is balanced by eating potassium containing foods and removal of excess potassium in the urine. Removal of excess potassium in the urine may be inadequate in a patient with chronic kidney disease and can lead to the accumulation of a high level of potassium in the blood (a condition known as hyperkalemia).

The risk of hyperkalemia is less in patients undergoing peritoneal dialysis compared to those on hemodialysis.

The risk differs in both groups because the process of dialysis is continuous in peritoneal dialysis while it is intermittent in hemodialysis.

High potassium levels can cause severe muscle weakness or an irregular heart rhythm that can be dangerous.

When potassium is very high, the heart can stop beating unexpectedly and cause sudden death. High potassium levels can be life threatening without noticeable manifestations or symptoms (and therefore it is known as a silent killer).To avoid serious consequences of high potassium, CKD patients are advised to restrict potassium in diet.

What is normal potassium level in blood? When is it considered high?

The normal serum potassium (level of potassium in blood) is 3.5 mEq/L to 5.0 mEq/L.

When the serum potassium is 5.0 to 6.0 mEq/L, dietary potassium needs to be limited.

When the serum potassium is greater than 6.0 mEq/L, active medical intervention is needed to reduce it.

A serum potassium greater than 7.0 mEq/L is life threatening and needs urgent treatment such as emergency dialysis.

Classification of food according to potassium content:

To maintain proper control of potassium in blood, food intake must be modified as per the doctor’s advice. On the basis of potassium contents, foods are classified into three different groups (high, medium, and low potassium containing foods).

High potassium = More than 200 mg/ 100 gms of food

Medium potassium = 100 to 200 mg/ 100 gms of food

Low potassium = Less than 100 mg/ 100 gms of food

Foods with high potassium content

Fruits: Fresh apricot, ripe banana, chico, fresh coconut, custard apple, gooseberry, guava, kiwi fruit, ripe mango, oranges, papaya, peach, pomegranate and plum

Vegetables: Broccoli, cluster beans, coriander, drumstick, mushroom, raw papaya, potato, pumpkin, spinach, sweet potato, tomatoes and yam

Dry fruits: Almond, cashew nut, dates, dry figs, raisins and walnut.

Cereals: wheat flour

Legumes: Red and black beans and mung (monggo) beans

Non-vegetarian food: Fish like anchovy and mackerel; shell fish like prawns, lobster and crabs; and beef

Drinks: Coconut water, condensed milk, buffalo milk, cow milk, chocolate drinks, fresh fruit juices, soup, beer, wine and many aerated drinks

Miscellaneous: Chocolate, chocolate cake, chocolate ice cream, Lona salt (salt substitute), potato chips and tomato sauce

Foods with Medium Potassium Content

Fruits : ripe cherries, grapes, lychees, pear, sweet lime and watermelon

Vegetables: Beet root, raw banana, bitter gourd, cabbage, carrot, celery, cauliflower, French beans, okra (ladies finger), raw mango, onion, radish, green peas, sweet corn and safflower leaves

Cereals: Barley, general purpose flour, noodles made from wheat flour, rice flakes (pressed rice) and wheat vermicelli

Legumes: red and black beans and mung (monggo) beans

Non-vegetarian food: Liver

Foods with Low Potassium Content

Fruits : Apple, blackberries, lemon, pineapple and strawberries

Vegetables : Bottle gourd, broad beans, capsicum, cucumber, garlic, lettuce, green peas, raw mango and pointed gourd

Cereals : Rice, rava and wheat semolina

Legumes : Green peas

Non-vegetarian food : Beef, lamb, pork, chicken and egg

Drinks : Coca-cola, coffee, lemonade, lime juice in water, and soda

Miscellaneous : Cloves, dried ginger, honey, mint leaves, mustard, nutmeg, black pepper and vinegar