The Ultimate Electrolyte and Supplement Guide for Intermittent Fasting
Voice of the Audience
“What vitamins can I take while fasting since my stomach be empty? Can I lift weights Can I do cardio Can I drink water”
— YouTube comment
“So how do you get the B vitamins, minerals and salt if you eat nothing?”
— YouTube comment
“Does my electrolyte powder break my fast?”
— YouTube comment
Developed from thousands of real YouTube comments and expert insights from Andrew Huberman, Dr. Eric Berg, Dr. Jason Fung, Dr. Sten Ekberg, and Dr. Alan Goldhamer. For deeper context and a full ranking of the top intermittent fasting videos, see our research-backed guide to intermittent fasting.
The Concern
Viewers want to know exactly which electrolytes and supplements are safe during a fast, how much to take, and when, without breaking a fast or blunting key benefits like autophagy. Many report lightheadedness, shakiness, fast pulse, or fatigue and suspect electrolytes or low blood sugar. There is also confusion about powders, multivitamins, and coffee add-ins that may add calories or trigger insulin.
The Tip
Prioritize electrolytes—especially sodium, and when needed potassium and magnesium—during fasting. Small, label-checked doses of plain minerals support hydration and can prevent common symptoms. Be cautious with electrolyte powders and supplements that include sugars, amino acids, or flavors; these can break a strict fast. When in doubt, keep the fast simple: water, optional black coffee or plain tea.
Creators Addressed
- Dr. Eric Berg — emphasizes ample salt and electrolytes; many viewers report salt is a “game changer” for lightheadedness and coldness.
- Andrew Huberman — suggests a pinch of salt in water to counter lightheadedness or shakiness; notes caffeine increases water and sodium loss.
- Dr. Jason Fung — fielded questions on electrolytes and supplements during prolonged fasts (36+ hours); practical stance favors electrolytes for longer fasts.
- Dr. Sten Ekberg — flags “too little water and minerals” as a key fasting mistake that leads to symptoms.
- Dr. Alan Goldhamer — runs medically supervised water-only fasts without supplements; electrolyte issues are managed by monitoring and ending/restarting fasts when needed. This strict approach raises viewer safety questions outside clinic settings.
Related Raw Comments
- “Get enough salt and electrolytes.”
- “So how do you get the B vitamins, minerals and salt if you eat nothing?”
- “I suggest supplementing salt frequently when you fast. More than you think. Helps with light headed or cold.”
- “Does my electrolyte powder break my fast?”
Quick Summary (Do This Tonight)
On fasts longer than 12–16 hours, add a pinch of quality salt to each liter of water and avoid sweetened or caloric powders. Keep coffee black. If symptoms persist, shorten the fast and review electrolytes with a clinician.
How to Do It
- Sodium baseline — Start with a small pinch (about 1/4 tsp) of Himalayan pink or Celtic sea salt per liter of water. Adjust based on sweat, climate, and symptoms.
- Potassium support — If you get cramps, weakness, or palpitations, discuss potassium with your clinician. Many prefer taking it during the eating window unless medically directed.
- Magnesium for calm/sleep — Consider magnesium (often glycinate or citrate) for cramps or sleep quality, preferably in the eating window to reduce GI upset.
- Read every label — Check electrolyte powders and multivitamins for sugars, amino acids, carbs, and calories. “Natural flavors,” sweeteners, or collagen can break a strict fast.
- Hydrate enough — Drink plain water consistently. Caffeine increases fluid and sodium loss; compensate with water and salt if you drink coffee or tea.
- Keep the fast clean — For stricter goals (autophagy, gut rest), stick to water and optionally black coffee or plain tea. Avoid MCT oil, creamers, or “bulletproof” drinks.
- Listen to warning signs — Persistent dizziness, tachycardia, or extreme fatigue are stop signals. Break the fast gently and seek medical advice.
Common mistakes & fixes
- Using sweetened electrolyte powders — Fix: Choose plain mineral salts with no sugars, amino acids, or calories.
- Adding cream, milk, or collagen to coffee — Fix: Use black coffee during fasting hours; add extras only in your eating window.
- Zero salt on longer fasts — Fix: Add a measured pinch of salt per liter; increase fluids as needed.
- Taking multivitamins mid-fast — Fix: Move most vitamins to your eating window unless your clinician advises otherwise.
- Ignoring symptoms — Fix: Shorten the fast, rehydrate, add electrolytes, and consult a clinician if symptoms persist.
Quick Answers (FAQ)
Do electrolytes break a fast?
Small amounts of plain mineral salts (sodium, potassium, magnesium) typically do not break a fast for most goals. Watch for hidden sugars or calories in powders.
How much salt should I use?
A common starting point is about 1/4 teaspoon per liter of water. Adjust to climate, activity, and how you feel. People with hypertension or kidney disease must consult their clinician.
What about multivitamins?
Many contain sweeteners, oils, or fillers. When possible, take multivitamins in your eating window or get personalized advice for extended fasts.
Does black coffee break a fast?
Plain black coffee is generally fine. Cream, milk, collagen, sweeteners, or “bulletproof” blends can break a strict fast or alter insulin.
Should I add magnesium or potassium?
If you have cramps, palpitations, or poor sleep, discuss magnesium and potassium with a clinician to determine type and dose that are safe for you.
Bottom line
Clean fasting works best with simple rules: hydrate, salt sensibly, avoid hidden calories, and respect your signals. For longer or medically complex fasts, partner with a clinician who understands electrolytes, medications, and your health history.
Medical note: Fasting can interact with health conditions and prescriptions. Seek medical guidance before extended fasts or supplement changes.
Looking for the Best of the Best?
See our research-backed comparison of the top fasting videos (26M+ views, 36k+ comments analyzed) for rankings and deeper context.
