Low Potassium Diet

What Is It, Uses, Foods to Avoid and Include, and More

Author: Ali Syed, PharmD

Editor: Alyssa Haag

Editor: Emily Miao, PharmD

Editor: Kelsey LaFayette, DNP, ARNP, FNP-C

Illustrator: Jessica Reynolds, MS

Copyeditor: David G. Walker

Modified: Aug 29, 2023

What is potassium?

Potassium is a mineral found in many types of food and beverages. Potassium maintains regular fluid balance and ensures proper nerve, skeletal muscle, and heart function when present within normal limits in the human body. A normal serum potassium level may range from 3.5 to 5 millimoles per liter (mmol/L) with minor differences in range based on different laboratories or assays. A serum potassium level higher than 5 mmol/L is defined as hyperkalemia, which may be characterized by an irregular heartbeat (i.e., arrhythmia), heart palpitations, shortness of breath, chest pain, nausea, or vomiting—with signs and symptoms particularly pronounced with levels above 6 mmol/L. A serum potassium level lower than 3.5 mmol/L is defined as hypokalemia, which may be characterized by muscle weakness, cramps, twitches, and/or irregular heartbeat—particularly at levels below 3 mmol/L.

Kidney unable to excrete excess potassium.

What is a low potassium diet?

A low-potassium diet consists of consuming foods that are low in the mineral potassium. While the recommended amount of potassium per day for adults is generally between 3,500 and 4,500 milligrams (mg), a low-potassium diet recommends between 2,000 to 3,000 mg of potassium per day.

What conditions can benefit from a low potassium diet?

Conditions that may benefit or require a low potassium diet include those that primarily affect the kidneys, which are the organs mainly responsible for maintaining potassium within normal range. Examples of conditions that may require a low potassium diet include chronic kidney disease, uncontrolled diabetes mellitus, and Addison disease (i.e., primary adrenal insufficiency). These conditions, as well certain medications like renin-angiotensin-aldosterone system (RAAS) inhibitors (i.e., ramipril) or aldosterone antagonists (i.e., spironolactone), can lead to increased serum potassium levels by impacting the kidneys’ ability to remove excess potassium from the blood into the urine. By limiting intake of potassium, the kidneys are not required to excrete as much potassium into the urine to maintain serum levels within normal range.

Other causes of hyperkalemia that may require a low potassium diet include dehydration, severe blood loss, or excessive intake of potassium-rich foods or supplements.

What foods are best on a low potassium diet?

Foods that are best to consume on a low potassium diet include certain fruits, such as apples and pears; certain vegetables, such as carrots, celery, and cucumbers; and carbohydrates, such as rice and bread products. Potassium content in vegetables can be reduced through a process called leaching in which raw or frozen vegetables are soaked in a large amount of warm water for at least two hours. This is followed by draining the water and rinsing the vegetables with warm water before cooking them. Leaching allows for some of the potassium to be extracted. While low potassium foods can be eaten regularly, it is crucial to limit the serving size in those with predisposing conditions (e.g., CKD) as potassium can quickly accumulate when large portions are ingested.

What foods should be avoided on a low potassium diet?

High potassium foods that should be avoided on a low potassium diet include fruits, such as bananas, oranges, and dried fruits; certain vegetables, such as potatoes, avocados, and tomatoes; certain bean varieties, such as white beans or adzuki beans; nuts; seeds; milk; and yogurt.

What are the most important facts to know about a low potassium diet?

A low-potassium diet consists of consuming foods that are low in potassium. Potassium is a mineral found in many types of food and beverages and serves various functions in the human body. A serum potassium level higher than 5 mmol/L is defined as hyperkalemia and a serum potassium level lower than 3.5 mmol/L is defined as hypokalemia. Conditions that may require a low potassium diet include chronic kidney disease, uncontrolled diabetes mellitus, and Addison disease. Foods that are best to consume on a low potassium diet include apples and pears; vegetables, such as carrots and cucumbers; and carbohydrates, such as rice and bread products. High potassium foods that should be avoided on a low potassium diet include bananas, oranges, and dried fruits; vegetables, such as potatoes, avocados, and tomatoes; and others.

References

Dunn JD, Benton WW, Orozco-Torrentera E, Adamson RT. The burden of hyperkalemia in patients with cardiovascular and renal disease. Am J Manag Care. 2015;21(15 Suppl):s307-s315.

Mayo Clinic. High potassium (hyperkalemia). Mayo Clinic. Published 2018. https://www.mayoclinic.org/symptoms/hyperkalemia/basics/definition/sym-20050776

National Kidney Foundation. Your Guide to a Low-Potassium Diet.; 2018. https://www.kidney.org/sites/default/files/NKF_Guide_to_Low_Potassium_Diet_Final_0.pdf

‌St-Jules DE, Clegg DJ, Palmer BF, Carrero JJ. Can Novel Potassium Binders Liberate People with Chronic Kidney Disease from the Low-Potassium Diet? Clinical Journal of the American Society of Nephrology. 2021;17(3):467-472. doi:https://doi.org/10.2215/cjn.09660721

‌van der Wijst J, Tutakhel OAZ, Bos C, et al. Effects of a high-sodium/low-potassium diet on renal calcium, magnesium, and phosphate handling. American Journal of Physiology-Renal Physiology. 2018;315(1):F110-F122. doi:https://doi.org/10.1152/ajprenal.00379.2017