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Having low potassium levels, or hypokalemia, may give rise to a range of symptoms, including muscle cramping and weakness, fatigue, and general malaise. Severe hypokalemia can also be life threatening.

People may experience hypokalemia as a result of following a ketogenic, or keto, diet. Certain medications and underlying medical conditions can also lower potassium levels.

This article will discuss the role of potassium within the body and suggest some reasons that a person may need to take a potassium supplement.

It will also provide information on dosages and possible side effects and list three of the best potassium supplements available.

Dietary potassium refers to potassium that comes from foods. Many different plant and animal foods contain potassium. Some examples include:

  • fruits, including dried fruits
  • nuts
  • legumes
  • brown rice
  • whole wheat flour
  • milk
  • yogurt
  • meat

The body absorbs about 85–90% of dietary potassium.

Potassium plays a major role in maintaining the water content of cells. It is also essential for:

  • nerve transmission
  • muscle contractions
  • proper kidney function

Most of the potassium in the body is stored inside cells. Normal concentrations of potassium in the blood range from around 3.6 to 5 millimoles per liter.

Blood potassium levels can give some indication of potassium status, but they cannot indicate what the stores are like inside the cells.

In otherwise healthy people with normal kidney function, abnormally low or high levels of potassium in the blood are rare.

However, certain factors can decrease potassium levels. Some examples include:

People who have any of the above risk factors may benefit from taking a potassium supplement.

Potassium supplements and the keto diet

Keto diets are high fat, low carbohydrate, moderate protein diets. Some people follow a keto diet to assist with weight loss. Doctors may also recommend these diets for people with the following conditions:

  • drug resistant epilepsy
  • glucose transporter type 1 deficiency syndrome
  • pyruvate dehydrogenase deficiency

The keto diet increases the acidic environment of the body. This can trigger a condition called metabolic acidosis (MA), in which the blood becomes too acidic. This can lead to kidney problems and a loss of bone mineral density.

One 2020 study suggests that oral potassium citrate supplementation may prevent the risk of MA in children following a keto diet. The researchers suggest that potassium citrate acts as an alkalizing agent to counteract the potential for MA.

Further studies are necessary to determine whether or not everyone following a keto diet should take a potassium citrate supplement.

It is also important to note that experiencing MA due to following a keto diet is extremely rare in people without a preexisting health condition.

Most dietary supplements contain potassium salts. A potassium salt is a combination of potassium and one or more other elements.

Dietary potassium supplements typically contain potassium chloride. However, some contain other potassium salts, such as:

  • potassium citrate
  • potassium phosphate
  • potassium aspartate
  • potassium bicarbonate
  • potassium gluconate

Since these different salts contain different amounts of potassium, the supplement label may show the amount of pure, or elemental, potassium in the product.

Multivitamin and mineral supplements that contain potassium typically contain about 80 milligrams (mg) of elemental potassium. Potassium-only supplements contain up to 99 mg of elemental potassium.

Different supplements will contain different amounts of potassium, so people should read the individual product labels to determine the appropriate dosages.

Potassium supplements can sometimes cause minor digestive side effects.

High doses of potassium can lead to high potassium levels, or hyperkalemia. However, this condition is rare among people with healthy kidney function, as the kidneys will excrete any excess potassium from the body.

People with impaired kidney function may experience hyperkalemia if they take in too much potassium. Hyperkalemia can cause the following symptoms:

Some of these effects can be life threatening.

Before taking a potassium supplement, a person should speak with a doctor. Most cases of hypokalemia are not solely due to a lack of potassium intake, so it is important to identify and treat the underlying cause of the hypokalemia.

If a person is considering taking a potassium supplement, they should ask their doctor or pharmacist for advice on dosage.

The National Institutes of Health (NIH) identify 221 dietary supplements that contain potassium. The sections below will outline three such products.

Please note that the writer of this article has not tried any of these products. All information presented is purely research-based.

NOW Supplements Potassium Citrate 99 mg

NOW Supplements Potassium Citrate 99 mg is a potassium supplement that is:

  • kosher
  • vegan
  • soy-free
  • nut-free
  • gluten-free
  • dairy-free
  • egg-free

The label suggests that this supplement helps support electrolyte balance, normal pH, and proper muscle contractions.

The dosage information states that a person should take one capsule one to five times daily with food.

NOW Supplements Potassium Citrate 99 mg is available for purchase online.

Nutricost Potassium Citrate 99 mg

Nutricost Potassium Citrate 99 mg is a non-genetically modified organism and gluten-free supplement.

The manufacturers recommend taking one capsule with eight to 12 ounces of water, or as a doctor suggests.

There are 500 capsules in each bottle.

Nutricost Potassium Citrate 99 mg is available for purchase online.

NaturalSlim Natural Potassium Citrate

NaturalSlim Natural Potassium Citrate contains 99 mg of potassium.

The manufacturers state that the product can improve metabolism for people who are trying to lose weight.

The dosage information states that a person should take two capsules for every 25 pounds of their body weight once per day.

NaturalSlim Natural Potassium Citrate is available for purchase online.

Experts suggest that more than 50% of people with low potassium levels may also have low magnesium levels. Magnesium deficiency may also contribute to potassium deficiency by increasing the loss of potassium in the urine.

People with low magnesium and low potassium should receive treatment for both deficiencies.

Many manufacturers of magnesium supplements claim that they can help prevent muscle cramps. However, a 2012 meta-analysis of seven randomized controlled trials concluded that magnesium supplementation is unlikely to provide clinically significant prevention of exercise- or disease-associated muscle cramps.

According to this meta-analysis, further research is necessary to determine whether or not magnesium supplementation is beneficial for pregnancy-related muscle cramps.

Potassium is essential for proper nerve transmission and muscle contractions. A lack of potassium in the body may cause muscle cramps, weakness, and fatigue.

People may develop hypokalemia as a result of an underlying medical condition, a side effect of certain medications, or following a keto diet.

Those with hypokalemia may benefit from potassium supplementation. However, they will need to see a doctor to determine the underlying cause of their hypokalemia.

People should speak with a doctor before taking any potassium supplement. Inappropriate use of potassium supplements can cause hyperkalemia, which can be life threatening.