Electrolyte drinks and tablets are sold without a prescription and are positioned as safe for anyone who does sports. However, for people with certain diseases, sodium, potassium, magnesium or calcium in a concentrated form can become not a help, but a burden. The editors systematized the conditions under which electrolyte supplements should be abandoned or used only under the supervision of a doctor.
General principle: who regulates salt balance
In a healthy body, electrolyte balance is maintained by the kidneys, heart, blood vessels, and adrenal hormones. The kidneys are able to remove a significant excess of sodium, potassium or magnesium, so a healthy person rarely gets problems even from a generous portion of an electrolyte drink.
The situation changes when one of the regulation links does not work fully. If the kidneys filter worse, the heart cannot cope with the volume of fluid, or drugs block the removal of certain ions, the "reserve of strength" disappears. Then a dose that is safe for a teammate may turn out to be excessive.
It is important to understand that it is not only about sick elderly people. Hypertension, hidden kidney problems, and taking blood pressure medications also occur in active middle-aged people who run marathons and do triathlons.
Therefore, before regularly using electrolyte supplements, it is useful to ask yourself honestly if you have any chronic diseases, if I take medication every day, and if my doctor has told me to limit salt or potassium. A positive answer to any of them is a reason for consultation.
Kidney diseases
Chronic kidney disease is a major limitation for electrolyte supplementation. With a decrease in filtration, the kidneys are less able to excrete potassium, magnesium, phosphorus and sodium. The KDIGO 2024 guideline for the management of CKD provides for individual control of potassium and sodium in the diet depending on the stage of the disease and tests.
Foods with a high potassium content are especially dangerous for people with CKD, including potassium chloride-based salt substitutes and "enriched" electrolyte powders. Hyperkalemia can develop asymptomatically, and the first manifestation is heart rhythm disturbances.
Magnesium also accumulates with reduced kidney function. Therefore, magnesium supplements, which in healthy people threaten only with diarrhoea, in patients with kidney failure can cause hypermagnesemia with weakness, a decrease in pressure and reflexes.
Urolithiasis should be mentioned separately. Excess sodium increases the excretion of calcium in the urine, which can contribute to the formation of stones. People with a history of stones, especially calcium stones, should not add salt and calcium supplements unnecessarily.
Heart, vessels and liver
With heart failure, the body tends to retain sodium and water, which leads to swelling and shortness of breath. The 2022 AHA/ACC/HFSA guideline (Heidenreich et al.) addresses sodium control as part of patient management. For such people, electrolyte drinks with sodium are unacceptable without consultation with a cardiologist.
Hypertension is the most common condition for which sodium should be restricted. The ACC/AHA clinical guideline (Whelton et al., 2018) recommends reducing its consumption to lower blood pressure. An athlete with hypertension may need sodium for a very long start in the heat, but the decision should be made by the physician.
People with cirrhosis and ascites also retain sodium, and many of them take spironolactone, which increases potassium levels. Electrolyte supplements in this case are dangerous from both sides — both because of sodium and because of potassium.
Conduction disorders of the heart, such as atrioventricular blocks, require caution with large doses of magnesium and potassium, as both ions affect the electrical activity of the myocardium.
| Condition | Problem electrolyte | Restriction level |
|---|---|---|
| Chronic kidney disease | Potassium, magnesium, phosphorus, sodium | Only as advised by a nephrologist |
| Heart failure | Sodium (sometimes potassium) | Only after consultation with a cardiologist |
| Arterial hypertension | Sodium | Limited, doctor's consultation |
| Cirrhosis with ascites | Sodium, potassium | Do not use without a hepatologist |
| Myasthenia gravis | Magnesium | Avoid magnesium supplements |
| Urolithiasis, hypercalcaemia | Sodium, calcium | Carefully, on the advice of a urologist |
| Diabetes | Sugar in beverages | Choose carbohydrate-free forms |
Medicines that change the balance of electrolytes
Many common drugs affect salt metabolism. ACE inhibitors, angiotensin receptor blockers, potassium-sparing diuretics increase potassium levels. Thiazide and loop diuretics, on the contrary, increase the loss of sodium, potassium and magnesium, and some antidepressants and antiepileptic drugs contribute to hyponatremia.
For a person who takes such drugs, the doctor often prescribes control blood tests for electrolytes. Independent addition of additives can "break" the carefully selected balance and make the results of analyzes unpredictable.
Magnesium and calcium reduce the absorption of some antibiotics (tetracyclines and fluoroquinolones), thyroid drugs and bisphosphonates. This is not a contraindication in the strict sense, but the doses should be separated in time on the advice of a doctor or pharmacist.
Editor's rule of thumb: If you take any blood pressure, heart, kidney, thyroid, or psychotropic medications on a daily basis, show the electrolyte product label to your doctor or pharmacist before starting regular use.
Children, pregnancy, special conditions
Children sweat less than adults, and their sodium needs during normal play and exercise are small. For most children, water and regular food are sufficient. Adult electrolyte tablets and capsules are not designed for children's body weight, so they should not be given without the advice of a pediatrician. Instead, for intestinal infections, doctors often recommend pharmacy ORS in children's dosage.
During pregnancy, fluid and sodium exchange changes, and in preeclampsia or gestational hypertension, salt control becomes part of the treatment. Pregnant women who continue to exercise should discuss their drinking strategy with their doctor and avoid supplements with caffeine or large doses of vitamins.
Myasthenia gravis is a rare but important contraindication to magnesium supplementation: magnesium impairs neuromuscular transmission and may exacerbate muscle weakness. People with phenylketonuria should avoid foods with aspartame, and people with diabetes should pay attention to sugar in drinks.
Elderly people have a reduced sense of thirst and are more likely to take medications that affect electrolytes. For them, any "sports" sodium and fluid recommendations need to be tailored with their doctor.
- Children: usually enough water; ORS - only according to indications and in children's forms.
- Pregnant: accept any supplements, especially with hypertension.
- Elderly: risk of both dehydration and hyponatremia.
- Hypertensive Athletes: Sodium Plan for Long Runs — Only with Physician.
Editorial conclusions
Electrolyte supplements are safe for most healthy people to use during prolonged or hot exercise. However, they are not universal.
Individual use should be avoided by people with chronic kidney disease, heart failure, uncontrolled hypertension, cirrhosis, myasthenia gravis, as well as those taking medications that retain potassium or alter sodium balance.
Children, pregnant women and the elderly may need electrolytes, but their choice and dosage should be agreed with the doctor and not copied from recommendations for adult athletes.
Read more about risks in the article "Electrolytes side effects", about correct use - "How to take Electrolytes: dosage, time of administration, duration", and about basic physiology - "Electrolytes: what it is and how it works".
List of used literature
- Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. KDIGO 2024 clinical practice guideline for the evaluation and management of chronic kidney disease. Kidney Int. 2024;105(4S):S117âS314.
- Heidenreich PA, Bozkurt B, Aguilar D, et al. 2022 AHA/ACC/HFSA guideline for the management of heart failure. Circulation. 2022;145(18):e895âe1032.
- Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults. Hypertension. 2018;71(6):e13âe115.
- Institute of Medicine. Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride. Washington, DC: National Academies Press; 1997.
- American Diabetes Association Professional Practice Committee. Standards of Care in Diabetesâ2024. Diabetes Care. 2024;47(Suppl 1).
- World Health Organization. Guideline: Sodium intake for adults and children. Geneva: WHO; 2012.
- McDermott BP, Anderson SA, Armstrong LE, et al. National Athletic Trainers' Association position statement: fluid replacement for the physically active. J Athl Train. 2017;52(9):877â895.
