Are your electrolytes actually in balance?

Yes, though severity depends on the electrolyte. Chronic high sodium intake is associated with hypertension and cardiovascular disease. Potassium hyperkalemia can cause cardiac arrhythmia, but is extremely rare in people with healthy kidneys from supplements alone. Magnesium excess from supplements causes diarrhoea long before reaching dangerous levels. The IOM magnesium UL of 350mg/day (supplemental only) is set at the gastrointestinal symptom threshold, not a toxicity threshold.

LMNT contains 1,000mg per packet (43% of the 2,300mg CDRR in a single serving). Liquid IV contains 500mg. Drip Drop contains 330mg. Nuun tablets contain 300mg. For context, average US dietary sodium is approximately 3,400mg. Adding LMNT brings the total to 4,400mg, nearly double the limit.

Yes, substantially. A sedentary person loses 500-1,000mg of sodium through sweat daily. An athlete training 2+ hours in heat can lose 2,000-5,000mg per session. ACSM recommends athletes replace electrolytes lost through sweat during sessions exceeding 60 minutes. This is the context where high-sodium products make physiological sense. Marketing has extended these products to sedentary populations who do not have the losses that justify supplementation.

The only way to know actual blood electrolyte levels is a medical blood test, specifically a basic metabolic panel (BMP) or comprehensive metabolic panel (CMP). These measure serum sodium, potassium, chloride, and bicarbonate. Magnesium is not included in a standard BMP and must be ordered separately. Dietary intake estimates like this calculator correlate with but do not directly measure blood levels.

The primary driver is processed and restaurant food, not table salt. Approximately 70-75% of dietary sodium comes from packaged and prepared foods, with only 5-10% added at the table or during cooking. A single restaurant meal can easily contain 2,000-3,000 mg. Common high-sodium foods include bread (100-200 mg per slice), processed meats (500-1,000 mg per serving), and soup (700-1,200 mg per serving). Staying under the 2,300 mg CDRR requires actively choosing low-sodium options at almost every meal.

For the vast majority of healthy adults, yes. The IOM did not set a UL for potassium in healthy individuals because kidneys efficiently excrete excess. However, potassium supplementation is potentially dangerous for people with chronic kidney disease, or those taking potassium-sparing diuretics, ACE inhibitors, or ARBs. The FDA limits over-the-counter potassium supplement doses to 99 mg per serving. If you have healthy kidneys and are not on the medications listed, potassium supplementation within the AI range is considered safe.

The IOM set the Tolerable Upper Intake Level for magnesium at 350 mg per day from supplements only, this UL does not apply to magnesium from food. The threshold was established based on the dose at which supplemental magnesium causes osmotic diarrhoea, not systemic toxicity. A person consuming 400 mg from food plus 350 mg from a supplement (total 750 mg) is not exceeding the UL, because only the supplemental portion is counted. The UL is a gastrointestinal tolerance limit, not a danger threshold.

Yes. Both low and high levels of potassium and magnesium can cause cardiac arrhythmias, including palpitations and irregular heartbeat. Hypokalemia (low potassium) is the most common electrolyte cause of palpitations and can result from inadequate dietary intake, excessive sweating, or diuretic use. Low magnesium can trigger palpitations independently and also worsens hypokalemia by impairing potassium retention. If you experience persistent heart palpitations, a basic metabolic panel (BMP) blood test is the appropriate diagnostic step.

For most sedentary or lightly active adults eating a typical Western diet, additional sodium supplementation is unnecessary and potentially counterproductive, as average dietary sodium already exceeds the CDRR. However, potassium and magnesium supplementation may be beneficial regardless of activity level. The most evidence-based approach for inactive people is to reduce processed food (lowering sodium) and increase fruits, vegetables, and legumes (increasing potassium and magnesium), rather than adding supplements. Electrolyte supplements were designed for people with high sweat losses.