Potassium: Benefits, Side Effects & Dosage

  • 1

Potassium is an essential mineral in the body and is vital for a variety of different processes. A potassium-rich diet has many health benefits, and there is evidence to suggest that it may help to reduce the risk of kidney stones and osteoporosis while reducing blood pressure. It may even help to reduce water retention.

What is Potassium?

Potassium is abundant in the human body. Approximately 98 percent of the body’s potassium is present in the cells (x). And of that 98 percent, 80 percent is located in muscle cells. The remaining 20 percent is found in the blood cells, liver and bones.

When you consume potassium, it acts as an electrolyte. The body uses it to conduct electricity, which is necessary for processes like sending nerve signals, contraction of muscles and the maintenance of fluid balance. That is why having the necessary amount is highly critical to your overall well-being.

Where Does it Come From?

Potassium is the eighth-most available mineral on earth (x). The earth’s crust is comprised of about 2.1 percent potassium. Most of the potassium that we get comes from the foods in our diet. Those foods are often bananas, raisins, cooked spinach, honeydew, cantaloupe, apricots, oranges, grapefruit, prunes, dates and cooked broccoli.

It is also possible to supplement with potassium — most commonly in the forms of potassium nitrate and potassium chloride (which is extracted from the minerals potash and sylvite).

Potassium and Fluid Regulation

Potassium is essential for many of the body’s processes to function. The body is made up of about 60 percent water, and 40 percent of that water is found in the cells. The fluid in the cells is called intracellular fluid. The remaining fluid is found outside of the cells in different parts of the body like the blood, in between the cells and the spinal fluid. The amount of intracellular fluid is regulated and affected by electrolytes — particularly sodium and potassium.

The main electrolyte in the cells is potassium, and it determines how much water is in the cells. Sodium, the other main electrolyte, is found in the extracellular fluid, or fluid that is found outside the cells. Its job is to determine the amount of fluid that resides outside the cells.

The number of electrolytes within the fluid is called osmolality. Normally, osmolality is equal between the inside and the outside of a body’s cells. In healthy conditions, there is a balance between the fluid that rests inside and outside of the cells.

When there is an imbalance, the side that has more water will move to the side that has less to find equilibrium between the two. When osmolality is not in balance, it might cause the cells to get smaller as the fluid moves out of the cell. It may also cause cells to enlarge if fluid rushes into the cell — just an example of why potassium is so vital to fluid balance in the body. If you don’t have enough potassium in the body, it can lead to dehydration, which can adversely affect the kidneys and heart (x).

Potassium and the Nervous System

The nervous system requires communication between the body and the brain. They send messages to each other through nerve impulses to regulate things like muscle contractions, reflexes, your heartbeat and many other important functions of the body. Nerve impulses are initiated by sodium ions that move into cells, followed by potassium that moves ions out of the cells. When the ions move, it changes the electrical charge of the cell, and that activates nerve impulses.

When there is a drop in the amount of potassium in the body, it can affect nerve impulses (x). That can adversely affect the nervous system and stop nerve impulses, which disrupts the ability of the brain and the body to communicate. Therefore, having the proper amount of potassium is essential for the nervous system to function.

Potassium and Muscle and Heart Contractions

The nervous system is responsible for regulating muscle contractions. When there is an alteration of potassium levels in the body that affects the nervous system’s communication, it can lead to a weakening of the muscle’s ability to contract. Both high and low blood levels of potassium can affect a body’s nerve impulses and alter the electricity of a cell (x).

Potassium is also essential for the health of the heart. Nerve impulses control the way that the heart beats. When blood potassium levels are too high, the heart can become flaccid and dilated. When that happens, it can weaken the heart’s ability to maintain a normal heartbeat rhythm. If levels are too low, it can also lead to an irregularity of the heartbeat.

If the heart doesn’t beat as it should, it negatively affects the amount of oxygen and blood that reaches the cells, organs and the brain. There are some instances where a heart arrhythmia, which is an irregular heartbeat, can lead to sudden death.

Potassium Benefits

Potassium Benefits

Lowers Blood Pressure

In America, high blood pressure affects nearly one out of every three people (x). High blood pressure is a risk factor for heart disease and stroke. A diet that is rich in potassium might help the body to eliminate excess sodium and, as a result, reduce blood pressure. When sodium levels in the body are elevated, it can raise your blood pressure, especially for those individuals who already have high blood pressure.

An evaluation of 33 various studies concluded that when people who were diagnosed with high blood pressure increased their consumption of potassium, their systolic blood pressure went down by an average of 3.49 mmHg, and their diastolic blood pressure also went down by 1.96 mmHg (x).

Another study conducted with 1,285 people ages 25-64 found that people who consumed the most potassium benefited by a reduction in blood pressure when compared to those participants who ate less of it. The people who consumed a high amount of potassium had a systolic blood pressure that was 6 mmHg less and, on average, diastolic blood pressure 4 mmHg less than those who ate less (x).

Protects Against Heart Disease and Stroke

A stroke is the result of a lack of blood flowing to the brain. Nearly 130 thousand people die in America yearly due to stroke. Several studies point to potassium as a way to prevent stroke. In an evaluation of 33 studies that encompassed 128,644 people, researchers found people who consumed the most potassium reduced their risk of heart disease and stroke by as much as 24 percent when compared to those who did not (x). And when 11 studies were analyzed of 247,510 people, those who consumed the most potassium had a reduced risk of heart disease and stroke by 21 percent (x).

Arthritis Relief

The evidence that potassium reduces the symptoms of arthritis is inconclusive. But one study done in 2008, concluded that high levels were associated with an anti-pain effect. Those who supplemented with 6,000 milligrams of potassium in the study reported that they had a 33 percent reduction of pain symptoms (x).

Other Benefits and Uses

There is evidence to suggest that potassium helps to prevent osteoporosis. In a study of 62 women ages 45 to 55, researchers found that those who ate the most potassium had the greatest bone mass (x). And another study of 994 premenopausal women showed that those who consumed it regularly had more bone mass in their hip bones and lower back (x).

Potassium might also help to reduce the risk of kidney stones. Kidney stones are clusters of materials that form from urine that is too concentrated (x). Studies have shown that potassium citrate helps to lower the most common mineral responsible for kidney stones — calcium. It might also help with water retention. Research shows that taking it in high doses might help to reduce water retention because it increases urine production and lowers sodium levels (x).

Potassium in Foods

It is always best to get the proper vitamins and minerals that are necessary through the things that you eat. A potassium-rich diet is essential for good health. Foods that have a high amount of potassium are:

  • Bananas, oranges, honeydew, apricots, dried fruits, cantaloupe and grapefruit
  • Avocados
  • Nuts
  • Cooked spinach
  • Sweet potatoes
  • Peas
  • Cucumbers
  • Mushrooms

Other sources include potassium chloride or salt. However, if you have a deficiency, then it might be necessary to take a supplement.

Dosage and Instructions

Potassium supplements are taken orally and should be taken only under the direction of a physician. Make sure to take potassium supplements with a full glass of water. Do not chew, suck or crush tablets. This can release the supplement at once, which will only further the potential of adverse side effects.

Potassium Side Effects

There are potential side effects to getting too much or getting too little potassium. Estimates show that Americans consume far less than the recommended amount of potassium (x).

Too much potassium can potentially lead to an allergic reaction, although that occurrence is rare. An excess of potassium can also result in low blood pressure. Excessive amounts is not common and usually only occurs in those who have chronic kidney conditions, are taking blood pressure medications and those who have kidney function abnormalities. Some studies do show that taking too many supplements can lead to an overdose (x). It can also lead to overcoming the kidneys’ capacity to eliminate excess potassium.

The warning signs of a potential overdose are gastrointestinal problems, heart issues like arrhythmia, cardiac arrest and respiratory and neurological disturbances.

The Bottom Line

Potassium is an essential mineral that helps the body perform a plethora of functions. Having too much or too little can have an adverse effect on the body, though. This can lead to a host of health conditions. It is always best to get potassium from the foods you eat. But in rare instances, it might be necessary for you to supplement.

About the author

Ryan Quigley

Graduate of Longwood University in Virginia. Part-time sports journalist covering the Vegas Golden Knights.

Let's Be Friends