Keto Electrolyte Calculator

When carbohydrate intake drops, insulin falls, and lower insulin makes the kidneys excrete more sodium. Water follows the sodium, and potassium losses can rise too. That loss is behind much of the "keto flu": headache, tiredness, lightheadedness, and cramps in the first week or two. Getting enough sodium, potassium, and magnesium helps many people avoid or ease it.

A common range on a well-formulated ketogenic diet is 3,000 to 5,000 mg of sodium a day in total, from food, broth, and salt combined; fat-adapted people often sit toward the lower end. That is more than the general 2,300 mg guideline because of the extra sodium lost through the kidneys on keto. Heavy sweaters and very active people tend to need the upper end. If you have high blood pressure, heart failure, or kidney disease, or take diuretics, ACE inhibitors, ARBs, or potassium-sparing drugs, set your sodium with your clinician.

Keto flu is a set of symptoms (headache, tiredness, brain fog, irritability, cramps, nausea) that often appears in the first few days of cutting carbohydrate. Low sodium and fluid are a big part of it. Salting food more generously or drinking a cup or two of broth, eating potassium-rich foods such as avocado and leafy greens, and getting enough magnesium help most people. Symptoms usually ease within a week or two.

Sodium, usually yes: salting food and drinking broth covers it. Potassium, mostly: avocado, leafy greens, salmon, and mushrooms are good keto sources, and food should supply most of it. Magnesium is harder to reach from food alone, so some people add a supplement. Aim for 300 to 500 mg total, and keep supplemental magnesium at or below 350 mg a day (the NIH upper limit) unless a clinician advises otherwise.

Food is the better route for most people. The target here is 3,000 to 4,700 mg total a day, mostly from food, and never below the NIH Adequate Intake (2,600 mg for women, 3,400 mg for men). Over-the-counter potassium supplements in the US usually contain no more than 99 mg per pill, so they make little difference. Do not take potassium supplements or salt substitutes without medical advice if you have kidney disease, or take ACE inhibitors, ARBs, or potassium-sparing diuretics, because potassium can build up to dangerous levels.

Magnesium glycinate and magnesium citrate are well absorbed and commonly used; glycinate tends to be gentler on the stomach, while citrate and oxide are more likely to loosen stools. Total magnesium from food and supplements is typically 300 to 500 mg a day. Keep supplemental magnesium at or below 350 mg a day, the NIH upper limit for adults, unless a clinician advises otherwise; a supplement of about 200 to 350 mg on top of food is a common choice. People with kidney disease should not take magnesium supplements without medical advice.

For as long as you eat a ketogenic diet. The extra sodium loss is tied to low insulin, so it continues rather than being a one-off adjustment, though fat-adapted people often sit toward the lower end of the 3,000 to 5,000 mg sodium range. Many people find that by a few weeks in, with steady habits around salt and food, they no longer need to think about it much.

Many sports drinks contain a lot of sugar and can stop ketosis. Look for electrolyte products with no sugar and no maltodextrin, and check the label: some products sold as "electrolyte" drinks contain only small amounts of sodium. Compare the sodium, potassium, and magnesium per serving with your targets from this calculator.