Potassium in Food

Not all people with kidney disease need to follow a low potassium diet.  It depends on your blood potassium levels and kidney function.  If your blood potassium level rises above 5.5mmol/l, you may be recommended to eat less potassium. 

Sometimes there can be other causes for a high potassium level that will be looked at by the doctor first.  You don’t need to reduce potassium in your diet unless you have been advised to by your doctor or dietitian.

Potassium is a mineral found in many foods.  It helps our nerves, muscles and heart to work properly.  Our kidneys help to control the level of potassium in the blood.  Potassium not needed by the body is usually passed out in the urine.  The normal range for potassium in the blood is 3.5 – 5.3mmol/l.

When your kidneys are not working properly, potassium can build up in your blood.  A high level of potassium can be dangerous, as it can affect your muscles and heart.

Some food and drinks are higher in potassium. These include:

• Some fruits such as apricots, avocado, bananas and dried fruit
• Some vegetables such as mushrooms, parsnips, spinach and tomatoes
• Potatoes which have not been boiled such as chips and jacket potatoes
• Snacks such as potato crisps, nuts, chocolate and liquorice
• Drinks such as coffee, malted milk drinks and fruit juices
• Alcoholic drinks such as cider and strong ales
• Soups containing tomatoes and vegetables
• Salt substitutes such as Losalt, Saxa So low and Solo

If you have diabetes you may have been advised to eat more fruit, vegetables and nuts. Your dietitian can advise you on appropriate quantities and help you choose lower potassium food and drinks.

If you need to change your diet, you can ask your doctor about a referral to a dietitian for more advice.  You can find more information on Lifestyle - diet, fluids and exercise on the Kidney Care UK website.