The Link Between Diabetes and Potassium

Medically Reviewed by Minesh Khatri, MD on June 20, 2022
3 min read

There's some evidence that too little potassium -- a nutrient in foods like bananas, squash, and potatoes -- might have a link to diabetes.

The reason for the connection: The role of insulin in type 2 diabetes.

Weight gain is the main cause of type 2 diabetes. The hormone insulin moves sugar from your blood into your cells, to use for energy or put into storage. When you have extra fat, insulin can't move sugar into your cells as well, so your blood sugar rises.

If your potassium levels are too low, your body may make less insulin. That could lead to high blood sugar. Studies show that people with low potassium levels release less insulin, have higher blood sugar levels, and are more likely to get type 2 diabetes than those with normal potassium levels.

There isn't enough evidence to prove that low potassium directly causes diabetes. Still, it might be a good idea to have your doctor check your potassium level if you're already at risk for diabetes.

Your doctor can test your potassium level with a sample of your blood or urine. A potassium test is often part of a routine physical exam.

Women need 2,600 milligrams of potassium every day while men need 3,400 milligrams. Many Americans don't get enough potassium from their diet.

Certain medicines also lower potassium levels, including certain diuretic drugs that treat high blood pressure, which cause the kidney to put both sodium and potassium in the urine.

If you already have diabetes, low potassium could be due to a serious complication called diabetic ketoacidosis. When your body can't make enough insulin to use sugar for fuel, it breaks down fat to use as energy instead.

The breakdown of fat releases chemicals called ketones into your blood. They can build up to dangerous levels in your body and cause symptoms like thirst, nausea, weakness, and shortness of breath. The fluids and insulin your doctor gives you to treat diabetic ketoacidosis can make your potassium levels drop. The ketones themselves along with high blood sugar can lead to potassium loss through the kidney.

This would require hospitalization to get it back under control.

You need enough potassium for a lot of reasons. Too little can lead to high blood pressure and symptoms like constipation, tiredness, and muscle weakness.

One way to get more potassium is to eat foods that have lots of it, including things like:

  • Dried fruits like apricots, prunes, and raisins
  • Bananas
  • Vegetables such as squash, spinach, potatoes, and broccoli
  • Beans and lentils
  • Fortified milk and orange juice
  • Chicken breast, salmon, and beef

If you're still low on potassium, your doctor might recommend a supplement. Most dietary supplements contain potassium chloride, but some contain a form like potassium citrate or potassium phosphate.

Too much potassium is called hyperkalemia. It can be a problem in people with poorly controlled diabetes.

High blood sugar damages the kidneys, which normally remove extra potassium from your body. People with diabetes and high potassium are more likely to have heart problems and other complications.

Your doctor might suggest tips like these to lower your potassium if it's too high:

  • Eat a low-potassium diet.
  • Take diuretics or potassium binders to remove extra potassium.
  • Avoid salt substitutes, which are high in potassium.
  • Don't take herbal remedies until you've checked with your doctor.

Follow the diabetes treatment your doctor prescribed. Good blood sugar control will also help to keep your potassium at a healthy level.