We may only think of potassium in the context of bananas because we know these fun yellow fruits have a lot of it.
But what exactly does this nutrient do for us and how do we know if we don’t have enough?
Potassium is one of the electrolyte minerals, along with magnesium, calcium, sodium, chloride, and hydrogen phosphate (1). Electrolytes are responsible for conducting electricity through the body. Potassium is a positive ion that regulates heartbeat and muscle function and is present in every cell in the body.
Potassium and sodium work inversely in the body: the more sodium (a neutral atom) in the body, the less potassium. Conversely, the more potassium, the less sodium.
Sodium (salt) is necessary for normal cell function, too, but we’ve been warned about the negative effects of too much sodium due to its influence on increasing blood pressure and other potentially dangerous consequences.
In the body, potassium (2):
builds proteins and muscle
- breaks down and consumes carbohydrates
- regulates body growth
- regulates heartbeat
- moderates pH levels
- promotes digestion.
Causes of potassium deficiency may be as simple as not eating enough of the right foods (or eating too many high-salt foods).
Physical conditions that can contribute to low potassium include (3):
- kidney disease
- taking diuretics
- dehydration due to excessive perspiration, diarrhea, or vomiting
- magnesium deficiency
- antibiotic use
Since potassium is so important, it’s good to recognize the symptoms of potassium deficiency to get your mineral levels back to what they should be.
8 Signs You Have a Potassium Deficiency
Here’s what to look out if you suspect you might have a potassium deficiency.
1. Chronic Fatigue
Many lifestyle factors can contribute to fatigue. If, however, you regularly get 7-8 hours of uninterrupted sleep and still feel tired all the time, it may be due to inadequate potassium. Because potassium conducts electricity, it regulates how cells use and transmit energy. Fatigue may be due to cells not interacting as well as they should (and need to).
Potassium resides inside blood vessels and relaxes them. Sodium stays mostly outside of cells and promotes fluid retention. This relationship translates to alternating blood vessel constriction and increased pressure. (4) Maintaining a balance between the two maximizes the transmission of electricity and regulates fluids. (5)
As we mentioned, potassium and sodium are inversely related; if cells don’t have enough potassium, sodium can build up, causing increased amounts of fluid and resulting hypertension. Too much fluid can cause cells to swell and eventually burst. (6)
High blood pressure is often a precursor to cardiovascular disease and stroke and can affect the kidneys, libido, and neurological function.
3. Muscle Weakness, Spasms, or Cramps
Muscles use potassium when they move. Of course, we’re using muscles somewhere every nanosecond of every day. The greater the exertion, the more potassium is lost from muscle fibers. This is why it’s recommended that you take in electrolytes before, during, and after vigorous exercise: to maintain potassium and other muscle mineral levels, preventing muscles from going into spasm.
A “significant loss of K+ [potassium] occurs following prolonged dynamic exercise, and…complete recovery of muscle K+ is slow,” writes a study on potassium loss during exercise (7).
Without enough potassium, muscles can get weak, spasm, or cramp.
4. Heart Arrhythmia
The heart is a very powerful muscle and it doesn’t get to rest until, well, it will eventually give out. Potassium is critical for its function no less than any other muscle. Because potassium conducts electricity upon which the heartbeat relies, too little potassium can affect the rhythm of the heart, causing arrhythmia or palpitations.
Potassium is critical for its function no less than any other muscle. Because potassium conducts electricity upon which the heartbeat relies, too little potassium can affect the rhythm of the heart, causing arrhythmia or palpitations.
Cells in the heart expand and contract in accordance with the flow of potassium and sodium in and out, respectively. Without potassium, the heart won’t contract and it can go into cardiac arrest (heart attack). Also, low levels of potassium can make the heart beat inefficiently, inducing intermittent blood flow, which has the potential to cause heart failure and/or blood clotting. (8)
Because potassium affects heart rhythm, if potassium levels get too low and blood flow is affected, you can feel light-headed or dizzy. (9) If this happens often, it’s time to see your healthcare practitioner.
Proper digestion requires muscle contraction to move things along. Low potassium = poor muscle function = slowed digestion = constipation.
7. Tingling or Numbness
Nerves communicate with each other via electrical impulses. Electrolytes like potassium facilitate the process:
“Potassium enters the cell more readily than does sodium and instigates the brief sodium-potassium exchange across the cell membranes. In the nerve cells, this sodium-potassium flux generates the electrical potential that aids the conduction of nerve impulses. When potassium leaves the cell, it changes the membrane potential and allows the nerve impulse to progress. This electrical potential gradient, created by the ‘sodium-potassium pump’, helps generate muscle contractions and regulates the heartbeat,” writes Elson M. Haas, M.D. (10)
Impeded nerve function can result in tingling or numbness in the extremities.
8. Avoiding Processed Foods
Not so much a symptom but a factor promoting potassium deficiency, processed foods generally contain very high amounts of sodium. Too much sodium signals your body to retain water in an effort to dilute potentially dangerous levels in the blood. With inadequate potassium to offset high sodium intake, the balance between the two is skewed.
Getting Enough of the Good Stuff
The recommended daily amount of potassium for adults is 4700mg.
- Beet greens
- Collard greens
- Lima beans
- Pinto beans
- Prune, raisin
- Sweet potato
- Swiss chard
- White beans
- Winter squash
Oh, yes—and bananas, too.