When I say “electrolytes,” what do you think of? Maybe rowdy professional athletes dumping a cooler of some neon-colored sports drink over their coach’s head after winning the championship. Electrolytes have a much bigger role in winning than just soaking the coach. What do electrolytes do?
If you’re an endurance athlete or a keto dieter, you might already supplement electrolytes as part of your daily routine. But do you know why? What are electrolytes anyway, and why do you need them? Does everyone need electrolytes, and are you missing out if you aren’t taking electrolyte pills?
In fact, electrolytes are unsung heroes that allow your body to run smoothly. Too much or too little, and your health is seriously impacted. Thankfully, the body’s delicate system of checks and balances usually keeps everything operating as it should. Still, you need to be mindful of your electrolyte intake if you want to maintain optimal health. (And isn’t that what we all want?)
Electrolytes are minerals (and some proteins) that carry an electrical charge when dissolved in water. These positively or negatively charged ions play an essential role in a wide variety of metabolic processes. Electrolytes allow nerves to fire and muscles, including the heart, to contract; regulate acid-base balance; support hormone and tissue production; and maintain proper fluid balance within cells, interstitial fluid, and blood plasma.
There are many electrolytes in the human body, but the most important are:
Sodium, chloride, and bicarbonate are highly concentrated in blood plasma and interstitial fluid outside the cells. Potassium, phosphate, magnesium, and, to a smaller degree, calcium are concentrated within cells. The body regulates hydration status and acid-base balance by maintaining the right gradient, or concentration, of electrolytes in different fluid compartments. Water and electrolytes are constantly diffusing through membranes to preserve the delicate balances.
Cells also use active transport to “pump” electrolytes across membranes using ion channels. You may remember learning about the sodium-potassium pump in high school biology class. Active transport of these electrolytes across the cell membrane is how nerve, muscle, and endocrine cells generate impulses and fire.
Most people get all the electrolytes they need through a healthy diet. Some folks—notably those following a ketogenic diet and endurance athletes—may need additional supplementation.
Electrolyte Balance and Imbalance
For the body to function properly, it needs the right amount of each electrolyte, and it needs them in the proper ratios.
In healthy individuals, electrolyte balance is tightly regulated by hormones, especially parathyroid and antidiuretic hormones and aldosterone. The kidneys filter water and electrolytes in the bloodstream, returning what the body needs to circulation, and excreting the rest. To a lesser extent, electrolytes are also excreted in stool, sweat, and respiration.
Electrolyte imbalances can occur with:
Improper hydration (too much or too little water)
Vomiting or diarrhea
Gastrointestinal disorders that interfere with absorption
Respiratory diseases like COPD
Certain medications like diuretics, beta-blockers, and corticosteroids
Trauma, burns, surgery
You might not notice any symptoms if you have a mild imbalance. Following a short illness, for example, if you return to eating your typical Primal diet and drinking a reasonable amount of water, your body will likely regulate itself without any major issues.
Signs that you might have a more serious imbalance include:
Loss of coordination
Nausea and vomiting
Specific symptoms depend on which electrolyte(s) are out of balance, and whether you have too little or too much. Very severe imbalances can even lead to seizures, coma, or death. Your doctor can test electrolyte levels with a simple blood test.
What Do Electrolytes Do, How Much Do You Need, and Where Do You Find Them?
Main functions in the body: Along with potassium, regulates the fluid volume in cells, interstitial fluid, and blood plasma. Needed for muscle contraction and generating nerve impulses.
Dietary sources: Most sodium in our diet comes from the salt we add to food. Much smaller amounts naturally occur in foods like beets, carrots, celery, and dairy products, and in drinking water. Someone eating a typical modern diet gets the bulk of their sodium from processed, packaged foods.
Recommended intake: In recent decades, doctors and the folks behind our governmental dietary standards have told us to limit sodium intake, mostly in the name of heart health. However, experts are increasingly challenging that advice. Multiple studies point to a greater risk of negative health outcomes with too little sodium123 Many believe that the current recommended daily intake of 1,500 mg per day for adults is woefully inadequate.
Instead, the sweet spot seems to be between 4 and 6 grams per day. That’s about 2 teaspoons of fine sea salt like Redmond Real Salt or a heaping tablespoon of kosher salt. (Remember, the salt we eat is not pure sodium, it’s sodium plus chloride—NaCl.) However, individuals with salt-sensitive hypertension or kidney disease will want to consult their doctors, as these populations probably do need to restrict sodium.
Main functions in the body: Along with sodium, potassium regulates fluid volume and allows for muscle contraction and nerve impulses. Regulates heartbeat.
Dietary sources: Fruits and vegetables. Bananas have become synonymous with potassium, but a medium potato actually contains twice as much potassium as a medium banana. Avocado is a better source as well. If your diet includes a variety of vegetables and perhaps some fruit, you are probably getting enough potassium.
Recommended intake: Adequate intake (AI) is 2,600 mg per day for adult females and 3,400 mg per day for males. The FDA’s recommended daily intake (RDI) is 4,700 mg per day.
While sodium gets most of the attention when it comes to heart health, potassium is at least as essential, if not more so. People with higher (but not excessive) potassium intake have lower blood pressure, less risk for cardiovascular disease, 4 and lower all-cause mortality.5
Research also suggests that the relative amounts of sodium and potassium you eat—the sodium:potassium ratio—is as important as the absolute amounts of each. You want to avoid high levels of sodium with low potassium. On the other hand, increasing potassium intake seems to offset the supposed dangers of higher levels of sodium intake (within reason).678
Main functions in the body: Maintaining fluid balance, which is vital for regulating blood pressure and pH of body fluids. Also a primary component of gastric juice in the form of hydrochloric acid.
Dietary sources: Mostly from added salt—sodium chloride and, to a lesser extent, potassium chloride. Seaweed and many vegetables also contain some chloride. You can also get chloride through the skin if you use a magnesium spray, which is usually magnesium chloride.
Recommended intake: 2.3 grams per day for adults up to 50, 2.0 grams per day up to age 70, 1.8 grams per day thereafter.
Main functions in the body: In addition to structural roles (bones and teeth), calcium helps muscles contract and nerves fire. Calcium also has a role in blood clotting.
Dietary sources: Leafy greens, broccoli, nuts and seeds, fish like sardines and anchovies where you eat the bones. Dairy products, if you consume them, are good sources as well despite any controversy about bioavailability.
Recommended intake: For adult females, 1,000 mg per day up to age 50, 1,200 mg per day thereafter. For males, 1,000 mg per day up to age 70, 1,200 mg per day thereafter.
When people talk about supplementing electrolytes, they generally mean sodium, potassium, and magnesium. For the average healthy person, you can meet your electrolyte needs by eating a varied diet rich in different vegetables, perhaps some fruit, and animal products, especially fish.
However, you may need to supplement if you eat a restricted diet or have certain health conditions such as gastrointestinal issues that interfere with your ability to absorb nutrients, or kidney or liver disease. Because supplements can interact with medications, talk to your doctor before starting any kind of supplement regimen.
Obviously, if you get an electrolyte panel done by your doctor, and it shows a deficiency, that’s another good reason to supplement. Likewise, if you’ve had a bout of vomiting or diarrhea, or if you’re having issues such as brain fog or muscle cramping. Don’t go overboard; it is certainly possible to have too much of any electrolyte. Drinking some salty bone broth or trying a standard dose of a potassium or magnesium supplement should be safe.
I should note, though, that dietary deficiencies in potassium are uncommon. It’s never a bad idea to track your food for a few days using an app like Cronometer. See how much you’re getting from diet so you can tailor your supplementing appropriately. It’s probably much more likely that you’re getting less sodium than you need if you’re eating mostly close-to-nature foods, especially if you’re hewing to conventional wisdom about restricting salt.
What Are the Best Forms of Electrolytes?
For sodium, all you need is good old salt. Different forms of salt contain varying amounts of sodium, so look at the label.
For potassium, I like potassium citrate. You can also use LoSalt or Nu-Salt, which contain potassium chloride. They are found with the table salt at your local grocery store. Some folks make their own electrolyte blend with cream of tartar (yes, the same stuff you bake with), which is potassium bitartrate. Any of these will work, but I think potassium citrate is the superior option.
For magnesium, the most bioavailable are the chelated forms that end in -ate. Different forms of magnesium are thought to have specific benefits, but magnesium malate or glycinate (also called bis-glycinate) are good all-around options. Magnesium L-threonate is particularly touted for cognitive benefits because it crosses the blood-brain barrier.
Is Potassium Supplementation Safe?
Because potassium is closely linked to heart function, there is a concern that supplementing potassium could lead to arrhythmias or even heart attacks. However, a 2016 meta-analysis of randomized controlled trials found no risk associated with supplementing within normal guidelines in healthy individuals.9People with heart or kidney problems should definitely talk to their doctors, though.
Although I think supplementing potassium is generally safe, it’s also reasonably easy to meet your potassium requirements through diet alone. Potassium supplements are limited to 100 mg per dose by the FDA anyway, which is a fraction of what you need.
Considerations for Keto Folks
If you’re following a keto diet, you probably do need to supplement. When you drop your carbs low enough for the liver to start making ketones, this also triggers a (normal) hormonal response that leads the kidneys to dump water. Along with water goes sodium and potassium especially. This can lead to low blood pressure, and it’s the reason why some people feel so crappy when they first go keto—-the dreaded “keto flu.”
If you’re eating a keto diet and your workouts are suffering, or you have low energy, headaches, or brain fog, low sodium and/or potassium is the likely culprit. Some people find that they need to supplement when transitioning into keto but not once they are keto-adapted. Others feel better if they continue supplementing.
In particular, many keto folks feel better when they increase their sodium considerably—3 to 5 grams above what they get from food, or perhaps even more.
Considerations for Athletes
Electrolytes, especially sodium and chloride, are lost through sweat, so many athletes use electrolyte supplements as a part of their training nutrition. This probably isn’t crucial for the average person working up a sweat at the gym. For hard-charging endurance athletes pounding away for hours, especially in intense heat, it might be the difference between making it to the finish line or not.
If you’re taking in a lot of water during a training session, it’s a good idea to add a pinch of salt, and perhaps a bit of carbohydrate, to your water. For one thing, this increases absorption. Drinking too much water without adequately replacing sodium losses can also lead to the dangerous, even fatal, condition of hyponatremia.10 I’m not a huge fan of most commercial electrolyte drinks due to their high sugar content, but it’s easy to make your own using one of the many online recipes. You can also use salt pills. It might take some tinkering to dial in the amount you need.
Some athletes also take sodium bicarbonate supplements in an attempt to offset exercise-induced acidosis. (Recall that bicarbonate helps maintain acid-base homeostasis.) Research shows that doses of 200 to 500 mg/kg may reduce lactate concentration and improve aerobic exercise performance and hand-eye coordination.11 Doses at the higher end of the spectrum seem to be more effective, but they can also cause undesirable gastrointestinal symptoms. If you experiment with this, make sure to take into account both the sodium and the bicarbonate you are adding and, if necessary, adjust your additional sodium supplementation accordingly.
Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.