A Perfect Balance: Avoiding Excess Sodium and Potassium Deficiency

It's also possible to consume too much potassium

By Roberta H. Anding, MS, Baylor College of Medicine and Texas Children’s Hospital
Edited by Kate Findley and proofread by Angela Shoemaker, The Great Courses Daily

Although sodium deficiency can be an issue for some, particularly athletes, most Americans consume too much sodium. Professor Anding explains the dangers of excess sodium and potassium, as well as potassium deficiency.

Table salt close up
A long-term consequence of sodium excess is elevated blood pressure, which can contribute to a shortened life expectancy. Photo By taa22 / Shutterstock

Excess Sodium Dangers

No upper safety limits have been established for sodium because excess amounts are generally filtered and excreted by the kidneys. However, excess consumption of sodium—more than the recommended 2,300 milligrams—is associated with high blood pressure, edema, and swelling due to fluid retention. 

High blood pressure as a disease state can lead to an increased risk of aneurysm, heart attack, heart failure, and stroke. Additionally, high blood pressure is the leading cause of chronic renal or kidney failure. 

Even a moderate elevation of arterial blood pressure can cause a shortened life expectancy, so we can view that indirectly as a long-term consequence of sodium excess. According to Professor Anding, this is why controlling or limiting your sodium intake is so vital. 

“When you have young children in the house, don’t salt their food,” Professor Anding said. “Salt tends to be an acquired taste, and so the more you introduce it in young children, the more likely they are to depend on it the older they get.”

Because sodium and potassium interact with one another, increasing potassium intake helps to lower blood pressure by blunting the effects of sodium. However, many Americans do not consume enough potassium. 

Potassium Deficiency

Some people even develop a potassium deficiency. Such deficiencies are rarely from dietary causes alone, but they can develop due to the over-excretion of potassium, which is often induced by medications such as diuretics. However, an often overlooked cause of low potassium is a low-carbohydrate diet which eliminates most fruits and vegetables.

Symptoms of potassium deficiency include fatigue, muscular weakness, confusion, anxiety, temporary memory loss, diarrhea or constipation, skin problems such as blisters and dryness, sleep disruption, and ringing or noise in your ear. However, some symptoms are vague and nonspecific. 

“Oftentimes, individuals who have low potassium will tell me, ‘I just don’t feel well. I can’t put my finger on it, but I just don’t feel well,'” Professor Anding said.

If these patients are taking one of the higher-risk medications, Anding will then investigate whether or not the medication is causing them to experience any deficiencies. 

Potassium Excess

As with most things, though, you don’t want to go too far in the opposite direction. Potassium excess, or hyperkalemia, is most often caused by abnormal kidney or renal functioning, resulting in ineffective elimination from the body. 

If, for example, you have long-term kidney disease and you end up on dialysis, you lose the body’s ability to get rid of the potassium excess. Unfortunately, for both potassium and sodium, the major route of excretion is in the urine.

It’s rare to get hyperkalemia from excessive potassium intake alone, but it can occur via salt substitutes. If you use a salt substitute, you’re getting rid of the sodium chloride, but you have to add some other kind of mineral to that chloride to have a taste, which often ends up being potassium chloride. 

If your doctor has told you to use a salt substitute, here’s a tip from Professor Anding. Potassium chloride salt substitutes get bitter when they’re heated. 

If you’re opening a can of unsalted green beans and you add a little potassium chloride, you might find a bitter or metallic aftertaste. Instead, then, add it at the end of the cooking cycle. As always, though, check with your doctor before making additions like this to your diet. 

Additionally, dietary supplements can be a source of excess potassium. If someone has had a potassium chloride infusion, or they don’t have normal kidney function, that can also cause hyperkalemia. 

The symptoms are similar to potassium deficiency: general malaise, heart palpitations or arrhythmias, muscular weakness, and sometimes sudden death in extreme cases of hyperkalemia. Therefore, though rare, potassium excess is still something you need to be aware of. 

Tomorrow’s article will explore practical tips for reducing sodium and increasing potassium.

This article was edited by Kate Findley, Writer for The Great Courses Daily, and proofread by Angela Shoemaker, Proofreader and Copy Editor for The Great Courses Daily.

Professor Roberta H. Anding is a registered dietitian and Director of Sports Nutrition and a clinical dietitian at Baylor College of Medicine and Texas Children’s Hospital. She also teaches and lectures in the Baylor College of Medicine’s Department of Pediatrics, Section of Adolescent Medicine and Sports Medicine, and in the Department of Kinesiology at Rice University.

About Kate Findley 408 Articles
Kate is a writer, novelist, and blogger living in Los Angeles. She has been writing for The Great Courses since 2017. It incorporates her two favorite things: writing and learning.