March 2026

What Are Electrolytes and Do You Actually Need Them?

The honest answer: probably not — unless you fall into a few specific groups.

Electrolytes are minerals that carry an electrical charge when dissolved in water. Your body uses them to conduct nerve impulses, contract muscles, regulate fluid balance, and maintain blood pH. The major electrolytes are sodium, potassium, magnesium, calcium, chloride, phosphate, and bicarbonate.

Most healthy adults eating a normal diet get all the electrolytes they need from food. But certain groups — heavy sweaters, people on keto or low-carb diets, people who fast, and those with conditions like POTS — lose electrolytes faster than food alone replaces them. For those people, supplementation is backed by real evidence. For everyone else, electrolyte products are mostly expensive water flavoring.

The Seven Electrolytes and What They Do

Electrolyte Key Functions Daily Need Top Food Sources
Sodium Fluid balance, nerve signaling, muscle contraction 3,000–5,000mg* Salt, bread, cheese, processed foods
Potassium Heart rhythm, muscle function, fluid balance 2,600–3,400mg Potatoes, bananas, beans, spinach
Magnesium 300+ enzyme reactions, muscle/nerve function, bone health 310–420mg Nuts, seeds, whole grains, dark chocolate
Calcium Bone structure, muscle contraction, blood clotting 1,000–1,200mg Dairy, fortified foods, leafy greens
Chloride Stomach acid production, fluid balance 2,300mg Table salt (NaCl), seaweed, tomatoes
Phosphate Energy production (ATP), bone structure, DNA 700mg Meat, dairy, nuts, beans
Bicarbonate Blood pH buffering, CO₂ transport Regulated internally Produced by the body; not a dietary need

Daily values based on NIH Office of Dietary Supplements recommendations for adults.[1][2] *The Dietary Guidelines recommend <2,300mg sodium, but the PURE study (Mente et al. 2014) found the lowest cardiovascular risk at 3–5g/day.[3]

Three of these get most of the attention in electrolyte products: sodium, potassium, and magnesium. Calcium and phosphate are abundant in most diets. Chloride comes along with sodium (table salt is sodium chloride). Bicarbonate is regulated by your kidneys and lungs, not diet.

Who Actually Needs Electrolyte Supplements?

The research supports supplementation for four specific groups.

Athletes and heavy sweaters. The American College of Sports Medicine recommends sodium-containing beverages for exercise lasting longer than one hour.[4] The average person loses about 966mg of sodium per liter of sweat, and sweat rates during exercise range from 0.5 to 2.0 liters per hour. At the high end, that's nearly 2,000mg of sodium lost per hour. Water alone doesn't replace it. In fact, drinking large amounts of plain water during prolonged exercise can dilute blood sodium to dangerous levels. A study of Boston Marathon runners found that 13% had hyponatremia (low blood sodium) at the finish line.[5]

Keto and low-carb dieters. When you restrict carbohydrates, insulin levels drop. Lower insulin signals the kidneys to excrete more sodium — a process called natriuresis. This is why many people experience headaches, fatigue, and cramps during the first week of keto (the "keto flu"). It's not carb withdrawal. It's electrolyte depletion. Phinney (2004) documented that ketogenic diets require deliberate sodium and potassium supplementation to maintain physical performance.[6] The practical recommendation is 3,000–5,000mg sodium per day on keto, significantly more than the standard dietary guidelines suggest.

People who fast. Fasting triggers the same insulin-driven sodium loss as keto, but faster. A 1975 study measured sodium excretion during extended fasting and found it peaks around day 4, driven by obligatory cation loss alongside ketone body excretion.[7] During a 24-hour fast, you're still losing sodium through urine but consuming zero. During multi-day fasts, the deficit compounds. Electrolyte supplementation during fasting is standard medical practice for supervised extended fasts.

POTS patients. Postural orthostatic tachycardia syndrome causes blood to pool in the lower extremities when standing. Standard clinical guidance recommends 3,000–10,000mg of sodium daily along with 2–3 liters of fluid to maintain blood volume.[8] At those sodium levels, food alone usually isn't enough. This is a genuine medical use case where electrolyte supplements serve a clinical purpose.

Who Probably Doesn't Need Them?

Most people eating a standard diet. Especially for sodium.

The Dietary Guidelines for Americans recommend less than 2,300mg of sodium per day. But emerging research suggests this target may be too low. The PURE study (Mente et al. 2014), one of the largest prospective studies on sodium and health outcomes, found the lowest risk of cardiovascular events and death at sodium intakes of 3–5 grams per day.[3] The average American consumes about 3,400mg/day[9] — which falls within that optimal range. If you're eating a typical Western diet with processed foods, restaurant meals, and table salt, you are almost certainly not sodium-deficient.

But that 3,400mg average is heavily driven by processed and restaurant food. If you eat paleo, keto, or carnivore — or simply cook most of your meals at home from whole ingredients — you may be getting far less sodium than you think. Unprocessed meat, vegetables, and eggs are naturally low in sodium. Unless you're intentionally salting your food, it's easy to fall well below the 3–5g/day range that the research suggests is optimal. For these groups, an electrolyte supplement or deliberate salting habit isn't a luxury — it's how you hit a reasonable baseline.

The NIH is equally direct about magnesium: "Symptomatic magnesium deficiency due to low dietary intake in otherwise healthy people is uncommon."[2] That said, 48% of the U.S. population does consume less magnesium than the estimated average requirement.[10] Sub-clinical insufficiency is common. Outright deficiency with symptoms is rare in healthy people.

If you exercise for under an hour, eat regular meals with adequate salt, and don't follow a restrictive diet, water is fine. Adding electrolytes won't hurt (your kidneys will excrete the excess), but it's unlikely to help either.

What About Potassium and Magnesium?

These two are the electrolytes worth paying attention to even if you eat a standard diet.

Potassium has an adequate intake of 3,400mg/day for adult men and 2,600mg/day for adult women.[1] The USDA considers it a "dietary component of public health concern" because so few Americans hit that target. But note: most electrolyte supplements contain only 200–400mg of potassium per serving. You'd need 8–17 servings to reach your daily need from supplements alone. Food is the realistic path here — one medium potato has ~900mg, one cup of cooked spinach has ~840mg, one banana has ~420mg.

Magnesium status has been declining for decades. Rosanoff et al. (2012) found that nearly half the U.S. population falls below the estimated average requirement.[10] Good dietary sources include pumpkin seeds (156mg per ounce), almonds (80mg per ounce), and dark chocolate (65mg per ounce). Most electrolyte supplements contain 40–60mg of magnesium per serving — a helpful boost, but not a substitute for dietary sources.

The exception is keto and low-carb diets. Cutting carbs eliminates many of the best potassium and magnesium sources (potatoes, beans, bananas, whole grains). On restrictive diets, supplements become a practical necessity, not a luxury.

The Bottom Line

Electrolytes are essential minerals. Your body cannot function without them. But "essential" doesn't mean "you need to buy a supplement." Most people eating a normal diet get adequate electrolytes from food.

Supplements make genuine sense if you exercise intensely for over an hour, follow a keto or low-carb diet, practice intermittent or extended fasting, or manage a medical condition that increases sodium needs. For those groups, the evidence is clear that deliberate electrolyte intake improves outcomes.

If you do need a supplement, the differences between brands are mostly sodium content and price. We compare 17 electrolyte brands by sodium, potassium, magnesium, price per serving, and cost per gram of sodium.

References

  1. National Institutes of Health, Office of Dietary Supplements. "Potassium — Fact Sheet for Health Professionals." Updated June 2024. NIH ODS
  2. National Institutes of Health, Office of Dietary Supplements. "Magnesium — Fact Sheet for Health Professionals." Updated June 2024. NIH ODS
  3. Mente A, O'Donnell MJ, Rangarajan S, et al. "Association of urinary sodium and potassium excretion with blood pressure." New England Journal of Medicine, 2014;371(7):601-611. PubMed
  4. Sawka MN, Burke LM, Eichner ER, et al. "American College of Sports Medicine position stand. Exercise and fluid replacement." Medicine & Science in Sports & Exercise, 2007;39(2):377-390. PubMed
  5. Almond CSD, Shin AY, Fortescue EB, et al. "Hyponatremia among runners in the Boston Marathon." New England Journal of Medicine, 2005;352(15):1550-1556. PubMed
  6. Phinney SD. "Ketogenic diets and physical performance." Nutrition & Metabolism, 2004;1(1):2. PubMed
  7. Sigler MH. "The mechanism of the natriuresis of fasting." Journal of Clinical Investigation, 1975;55(2):377-387. PubMed
  8. Dysautonomia International. "Lifestyle Adaptations for POTS." Dysautonomia International
  9. Jackson SL, King SMC, Zhao L, Cogswell ME. "Prevalence of Excess Sodium Intake in the United States — NHANES, 2009–2012." Morbidity and Mortality Weekly Report, 2016;64(52):1393-1397. CDC
  10. Rosanoff A, Weaver CM, Rude RK. "Suboptimal magnesium status in the United States: are the health consequences underestimated?" Nutrition Reviews, 2012;70(3):153-164. PubMed

Frequently Asked Questions

For most daily activities, water plus a normal diet provides all the electrolytes you need. Electrolyte supplements become relevant when you're sweating heavily for more than an hour, eating a very low-carb diet, fasting, or managing a condition like POTS.

Drinking only water during prolonged exercise can actually dilute your sodium levels — a condition called hyponatremia.

Yes. Excess sodium raises blood pressure in salt-sensitive individuals (about 25-50% of the population). Excess potassium can cause dangerous heart rhythm changes, especially in people with kidney disease. Excess magnesium from supplements can cause diarrhea.

For healthy people with normal kidney function, excess electrolytes are mostly excreted in urine, but moderation still matters.

For exercise under 60 minutes, water is sufficient for most people. For exercise over 60 minutes, especially in heat, the ACSM recommends beverages containing 500-700mg sodium per liter to maintain fluid balance.

The benefit is replacing what you actually lose in sweat, not some general hydration advantage.

Chemically, nothing. Sodium chloride from a potato is identical to sodium chloride in a supplement. The practical difference is dosing and timing. Food provides electrolytes gradually throughout the day alongside other nutrients.

Supplements deliver a concentrated dose quickly — useful mid-exercise or during a fast when you can't eat, but unnecessary if you're eating regular meals.

Partially. Alcohol inhibits antidiuretic hormone (ADH), causing increased urination and fluid loss, which depletes sodium and potassium. Replacing those electrolytes addresses the dehydration component of a hangover.

But hangovers also involve acetaldehyde toxicity, inflammation, and disrupted sleep — electrolytes don't fix any of those. They help, but they're not a cure.