Potassium: Benefits, Side Effects, Best Time to Take It & More

Potassium

(K)

Evidence: High
Possible Benefits: Reasonable
Safety: High

What is potassium?

Potassium is an essential mineral necessary for hydrating all cells inside the body, keeping blood pressure from getting too high, and more. Potassium supplements are only helpful if you are deficient in this nutrient. If you already get enough of this electrolyte from food, you should probably avoid potassium supplements as there are multiple risks associated with them. This article is about the main benefits of potassium as a supplement, its potential side effects, the best time to take it, and more.

What does potassium do?

The main function of potassium is to hydrate all cells inside the body.

While potassium itself cannot hydrate the cells in your body, it does so with a help of sodium. This process is called the sodium-potassium pump and consumes 20-40% of all body’s energy at rest.

Too much sodium increases the water content in the blood, which exerts more pressure on the walls of your blood vessels, causing high blood pressure. This increase in extracellular fluid can also lead to swelling.

Potassium can mitigate these risks to a great extent by moving excess sodium from the blood into the urine. This is why these electrolytes have to be kept in balance.

Balancing these nutrients may also be important to bone health and kidney health.

With a help of sodium, potassium allows neurons to respond to neurotransmitters or other signals, and to transmit signals to other neurons or muscle cells.

Potassium also activates several enzymes involved in energy metabolism, antioxidant defense, and repair.

Possible benefits

It is important to note that all of the potential benefits mentioned below are dose-dependent. Generally, the higher the dose, the more pronounced the effects are. However, they do reach a plateau at a certain point. We will discuss the best dosing protocol later in this article.

Many possible benefits fall under the umbrella of ‘correcting a deficiency’ and are therefore not mentioned in the article. If you are deficient, potassium supplements can affect your cognition, performance, and overall health in a remarkably positive way.

Major benefits

Correcting or preventing a deficiency – Potassium deficiency can be terrible for health and overall quality of life. Fortunately, a severe deficit is relatively rare. A mild deficiency is much more common and can lead to many problems mentioned later in the article. If you are experiencing symptoms of deficiency or know that your potassium levels are too low, helping you get back to the optimum is the main benefit of potassium supplements.

Minor benefits

Lowered blood pressure – This effect is most notable if you are either deficient in potassium or consume high amounts of sodium. Beware that taking very high amounts can cause blood pressure to drop too low.
Lowered blood sugar – The same said about blood pressure also applies to blood sugar as this electrolyte plays a central role in insulin release.
Reduced risk of stroke – Potassium from either food or supplements slightly decreases the risk of stroke. Those who consume at least 3500 mg of this mineral daily have about 24% lower risk than those who consume less. However, this is mostly because most potassium comes from whole plant foods such as legumes and vegetables.

Possible side effects

These side effects are dose-dependent. The risk for them increases (often linearly but sometimes exponentially) as you increase the dose. Some of the side effects only apply to very high doses.

Hyperkalemia – Hyperkalemia is a formal term for potassium toxicity. Potassium does not have an established limit of toxicity, but when blood levels of this mineral rise too high, your heart rate may increase, your heart may skip beats or flutter, and you may experience confusion, tingling, numbness, weakness, or the feeling of something crawling on your skin. In severe cases, high blood levels of potassium can be fatal.
Diarrhea – Diarrhea caused by this supplement is not dangerous (assuming it doesn’t lead to severe dehydration) and usually only occurs if you take very high doses at once. Potassium chloride is more likely to cause this side effect than other forms of this mineral. This effect can be reduced by mixing the supplement with water.
Nausea – Just like diarrhea, this side effect is not dangerous but can be unpleasant.
Too low blood sugar – Potassium plays a central role in insulin release. Since insulin lowers blood sugar levels, a high dose of potassium on an empty stomach may push your blood sugar too low.
Contamination – Contaminated supplements are uncommon in the USA and other well-regulated countries. However, if you wish to buy products from China, India, or other countries without strict regulations, beware that the supplements may be contaminated. Either way, you need to choose the brand you order from wisely. It is highly recommended to check the certificates or read through some reviews for the specific product before you buy it. The FDA (Food and Drug Administration) has the power to regulate dietary supplements but can only do so after they have been on the market for a while. That’s because supplement companies are not obligated to announce to the FDA when releasing a new product on the market. The FDA has to discover the product and test it for potential impurities, which can take a lot of time. During that time, the supplement can be sold on the market even if it’s impure. Also, supplement companies can change their manufacturers without announcing it to the FDA.

Who should not take potassium?

You should probably avoid taking the supplement if you:

already consume enough potassium from food
suffer from diabetes or insulin resistance
have impaired kidney function
experience a severe adverse reaction after taking the supplement
are on a fast (potassium can drop your blood sugar too low which can be dangerous, especially if you are in a fasted state)
take one of these: ACE inhibitors, angiotensin receptor blockers, potassium-sparing diuretics, alpha-blockers, beta-blockers, digitalis, heparin, Bactrim, pentamidine, or nonsteroidal anti-inflammatory drugs (NSAIDs)
consume low amounts of sodium
are on a tight supplement budget (since there are more cost-effective supplements on the market for most people)

Who will benefit the most?

You should consider taking the supplement if you:

experience symptoms of deficiency, or you know you are deficient based on blood tests
don’t get enough from food (the easiest way to find out how much of this nutrient you are getting in your diet is to track your food intake for a while with Cronometer.com)
consume high amounts of sodium (these two electrolytes have to be kept in balance as too much of one can deplete the other)
have a high budget for supplements (assuming that the supplement doesn’t contain impurities, it appears to be safe in most cases and rarely does more harm than good if you stick to regular doses)

Symptoms of potassium deficiency

The most common signs of deficiency include:

High blood pressure
Irregular heartbeat
Constipation
High blood sugar
Muscle weakness
Tingling
Numbness
Muscle cramps
Fatigue

Keep in mind that these signs are just indications of a deficiency. If you experience some or even most of them, it does not necessarily mean you need more potassium. On the other hand, some people may be deficient even though they are completely asymptomatic.

With that said, if you experience many or most of these symptoms, there is a high chance that you are not getting enough potassium. The more of these symptoms you have and the more severe they are, the more likely you are to have a deficiency.

Types of potassium supplements

The different types of potassium supplements include:

Potassium chloride – This form has a salty taste and is sometimes used as a salt substitute (Nu salt is a popular example). This form is unnatural and generally not ideal as chloride is likely to increase blood pressure. Potassium chloride still lowers blood pressure but significantly less than other forms without chloride.
Potassium bicarbonate – This form is significantly better at lowering blood pressure. Bicarbonate can neutralize the stomach acid by converting it to water, which can hurt digestion when you take this form with food. However, even this form is better taken with food to lower the risk of unwanted side effects.
Potassium citrate – This is the best form to take for most people.
Potassium iodide – This form should be seen as an iodine supplement as it doesn’t contain much potassium.
Potassium glycinate – This form contains 1 mg of potassium for roughly 2 mg of glycine. Glycine may improve sleep quality and helps with blood sugar control when taken with a meal.
Potassium aspartate – This form provides the amino acid aspartate, which may help boost exercise performance and endurance when taken at about 6.5 g per day. It contains about 3 mg of aspartate for every 1 mg of potassium.
Potassium gluconate – This form works just as well for increasing potassium levels in the body as most other forms.

Potassium from all forms above absorbs well. Except for potassium iodide, all forms contain high amounts of potassium and are very effective. Potassium citrate appears to be the best form to take for most people as it can be found naturally in food and has the best safety profile.

How much potassium should you take?

The minimum target for potassium is set at 3400 mg/d for adult men and 2300 mg/d for adult women. These amounts should be enough for most people to avoid symptoms of deficiency but they are generally not enough for optimal health.

The AI (adequate intake) for this nutrient is 4700 mg/d for adult men and women.

Most of our ancestors were consuming about 11000 mg/d. This amount may be a slightly better target from a health perspective but getting so much of this mineral from food would be very inconvenient.

For most people, 4700-11000 mg appears to be the best daily target. This amount should provide all of the benefits without meaningful side effects.

Potassium is needed to get rid of excess sodium and vice versa. Therefore, these two minerals should be kept in balance.

To prevent high blood pressure and other risks associated with high sodium intake, you should consume at least 1 mg of potassium for every 1 mg of sodium.

The upper safety limit for potassium has not been established. In healthy individuals who do not take medications that could interfere with potassium supplements, doses as high as 15 grams/day appear to be safe. However, there doesn’t seem to be any added benefit to going over 11 grams (from food and supplements combined).

Since potassium from supplements possesses more risks than potassium from food, doses any higher than 3 grams are unnecessary and likely to cause more harm than good.

Food sources of potassium

The richest food sources include vegetables, fruits, legumes, nuts, and seeds. The more of these you consume, the more likely you are to get enough potassium.

Junk food, animal products, oils, and most grains are typically very low in potassium. This makes it nearly impossible to get enough of this mineral on SAD or high-fat diets that don’t include high amounts of vegetables.

The easiest way to find out how much potassium you are getting in your diet is with Cronometer.com. This free app allows you to track all vitamins, minerals, and more.

Best time to take potassium

The nutrient is water-soluble so you don’t have to take it with food to absorb it well but taking the supplement with food is better if it causes stomach upset or low blood sugar when you take it on an empty stomach.

Do not take the supplement during a prolonged fast unless you have a great reason to do so. Potassium can cause your blood sugar to drop too low which can be dangerous.

Whether you take the supplement in the morning or the evening doesn’t matter. It does not interrupt your sleep in any way.

If you decide to take over 1 gram of this mineral, spread the dose to multiple smaller doses throughout the day.

Interactions with other supplements

Salt
Sodium and potassium must be kept in balance as too much of one can deplete the other.
ACE inhibitors
Angiotensin receptor blockers
Potassium-sparing diuretics
Alpha-blockers and beta-blockers
Digitalis
Heparin
Bactrim
Pentamidine
NSAIDs (nonsteroidal anti-inflammatory drugs)

Where to buy potassium

Amazon seems to be the best option for ordering potassium supplements in most countries. They offer some very affordable products backed by many positive reviews. Also, you can choose from a wide range of brands without having to search through other markets on the internet.

Beware some brands display the dosage per serving instead of per pill or capsule. Therefore, you may accidentally buy something less potent than you intended. Do not fall for this marketing trick.

FAQ

You can take the supplement daily and do not need to cycle it. However, it is certainly not a problem if you don’t take it daily. Not taking the supplement every once in a while could lead to better absorption.

All of these options are fine. The two most important things to consider are the price and dosing. Powders are almost always the cheapest form. However, you may need a highly accurate scale to dose them correctly (preferably 0.001g). You can get one for as little as $20 from Amazon. Dosing the powders also takes some time that can add up over months or years. The disadvantage of capsules is that they often contain bovine gelatine, which rarely comes from an ethical source.

Yes. The nutrient doesn’t impact your sleep in any negative way in the short term.

The supplements should not become harmful once they exceed the expiration date, but they can lose potency over time.

Keep the supplements in a cold, dark, and dry place, and they should remain just as potent for many months or even years.

The supplement doesn’t directly reduce acne, unfortunately.

While toxicity is rare, too much potassium from supplements can cause some health problems, such as gastrointestinal distress and low blood pressure. It is best to stay below 11 grams a day to prevent these side effects.

All types of potassium supplements are highly absorbable. Except for potassium iodide, all forms contain high amounts of potassium and are very effective. Potassium citrate appears to be the best form to take for most people as it can be found naturally in food and has the best safety profile.

The most common reason people become deficient is that they don’t get enough of this nutrient from their diet. A high sodium intake is another common cause of potassium deficiency as excess sodium forces potassium to flush sodium out through urine.

You may need more of the nutrient if you:
– experience signs of deficiency, or know that you are deficient from blood tests
– don’t get enough from food (the easiest way to find out how much of this nutrient you are getting in your diet is to track your food intake for a while with Cronometer.com)
– consume high amounts of sodium (these two electrolytes have to be kept in balance as too much of one can deplete the other)

The half-life of this electrolyte in the body is typically less than 7 hours. In some parts of the body, such as skeletal muscle, the nutrient has a half-life of up to 70 hours.

In the long term, it typically takes about a month of taking the supplement to begin noticing the benefits.

Most potassium supplements on the market are vegan-friendly but always check the label to be sure. If you buy the mineral in a capsulated form, beware that the capsules often contain animal-based gelatine. Instead, find a brand that puts its products into cellulose capsules.

The nutrient is water-soluble so you don’t have to take it with food to absorb it well. However, taking it with a meal is much safer.

No, it doesn’t. The supplement does not interfere with fasting in any significant way. However, taking the supplement during the fast is rarely necessary and can be very problematic as it can drop your blood sugar levels too low.

References

Most of the information provided in this guide is supported by scientific research that can be found and verified in the PubMed medical library. We highly encourage you to use the library to verify anything said in this article. We excluded from consideration studies that are either confounded or have a high conflict of interest.

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