Electrolytes are minerals that carry an electrical charge in the body. This is how they help transmit signals between nerves and muscles, maintain fluid balance, and regulate pH. The main ones include sodium (Na⁺), potassium (K⁺), magnesium (Mg²⁺), calcium (Ca²⁺), and chloride (Cl⁻). In practical terms, without them muscle contraction, heart rhythm, and the absorption of water from the intestines into the bloodstream wouldn’t work properly. A normal diet usually covers your needs, but in hot weather, during prolonged exercise, or with diarrhea or vomiting, losses can add up quickly.
Recommended intakes: what official authorities say
In Europe, the commonly used “adequate” daily intake of sodium for adults is 2 g, which corresponds to about 5 g of table salt (NaCl). This also applies to pregnant and breastfeeding women; for children and adolescents, recommendations are lower depending on age. These values are based on European dietary reference values (EFSA). (EFSA Journal)
For potassium, EFSA recommends an intake of 3,500 mg per day for adults. Higher potassium intake is generally associated with better blood pressure and fluid balance, but individual needs may vary depending on health status and physical activity level. (EFSA Journal)
When water is enough, when to choose a sports drink, and when to use ORS
For an ordinary day and shorter activity (up to ~60 minutes in moderate conditions), plain water and a varied diet rich in potassium and magnesium are usually sufficient. Sports drinks with electrolytes make sense for longer sessions, in high heat, and with heavy sweating—when sodium and performance may drop. If fluid loss is due to diarrhea or vomiting, the first choice is ORS (oral rehydration solution) formulated to the WHO/UNICEF standard—a glucose-and-salt solution designed to quickly replace water and minerals during gastrointestinal illness. ORS is formulated differently from sports drinks and is suitable for children as well; always follow the exact mixing instructions on the sachets. (World Health Organization)
Symptoms of electrolyte imbalance to watch for
Common warning signs include muscle cramps, weakness, headaches, dizziness, fatigue, palpitations or rhythm disturbances, and reduced exercise tolerance. With low sodium (hyponatremia), confusion and nausea may occur; with excessive sodium, marked thirst and worsened blood pressure are more typical. High potassium (hyperkalemia) is dangerous for the heart and mainly concerns people with kidney disease or those taking certain medications.
Safety of supplements and “salt substitutes”
“Salt substitutes” often replace part of the sodium with potassium chloride. For healthy people, this can be useful when reducing sodium, but high-potassium products are not suitable for everyone. If you have kidney disease, take ACE inhibitors, ARBs (sartans), or potassium-sparing diuretics, consult your doctor before using them—there is a risk of elevated blood potassium. (ods.od.nih.gov)
Food sources: how to get them naturally
We get sodium and chloride mainly from salt and processed foods; in a typical Central European diet, the more common issue is limiting intake. Potassium is abundant in potatoes (including baked with the skin), legumes, bananas, vegetables (tomatoes, spinach), dairy products, and fish. Magnesium comes from nuts, seeds, whole grains, and legumes. Over the long term, a balanced diet is the best way to keep electrolytes within a healthy range.
Practical tips for sports and summer
Start longer activities well hydrated and keep drinking regularly in smaller amounts. Watch the color of your urine (pale yellow is usually OK) and after training replenish not only fluids but also salt and potassium—for example with soup, potatoes, fermented vegetables, or yogurt with a saltier side. During very long efforts in the heat, the goal isn’t to drink “as much as possible,” but to replace losses sensibly to avoid both dehydration and overhydration from plain water.
When to see a doctor
If you develop severe dizziness, persistent vomiting or diarrhea, heart rhythm problems, cramps, a pressing headache, or confusion, don’t wait—contact a healthcare professional. Be especially cautious with supplements if you have kidney or heart disease, high blood pressure, or you take diuretics and other medications that affect mineral levels.
How to read labels without getting lost in the numbers
On food labels, check sodium (sodium/Na) in mg per 100 g or per serving. A practical rule of thumb: 2,000 mg of sodium equals about 5 g of table salt per day. With sports drinks, look for whether they actually contain sodium—and how much; an “electrolyte” drink without sodium hydrates less effectively when you’re sweating heavily. With gastrointestinal illness, use ORS sachets and follow the exact mixing instructions.
Video: What are electrolytes? (short and practical)
A short explanation from Cleveland Clinic—when you need them and why.
Sources
- EFSA Journal (2019): Dietary reference values for sodium – scientific opinion on the recommended sodium intake for the EU (2 g/day ≈ 5 g salt). https://efsa.onlinelibrary.wiley.com/doi/10.2903/j.efsa.2019.5778 (EFSA Journal)
- EFSA Journal (2016): Dietary reference values for potassium – scientific opinion on the recommended potassium intake (3,500 mg/day). https://efsa.onlinelibrary.wiley.com/doi/10.2903/j.efsa.2016.4592 (EFSA Journal)
- WHO/UNICEF (2006): Oral rehydration salts – monograph on the composition and use of ORS for diarrhea-related dehydration. https://www.who.int/publications/i/item/WHO-FCH-CAH-06.1 (World Health Organization)
- NIH Office of Dietary Supplements (2022): Potassium – Health Professional Fact Sheet – overview of potassium, including warnings about KCl-based “salt substitutes.” https://ods.od.nih.gov/factsheets/Potassium-HealthProfessional/(ods.od.nih.gov)
Jana
I like turning curiosity into words, and writing articles is my way of capturing ideas before they slip away — and sharing them with anyone who feels like reading.
