Expert Q&A

What vitamins should I be taking while doing intermittent fasting

Why Vitamins Matter During Intermittent Fasting

As the founder of CFP Weight Loss and author of The Fasting Reset, I've helped thousands of adults in their 40s and 50s lose weight safely with intermittent fasting. When you compress your eating window, you naturally reduce opportunities to get essential nutrients. This is especially critical if you've struggled with hormonal changes, joint pain, or managing diabetes and blood pressure. The right vitamins prevent fatigue, support metabolic health, and make fasting sustainable long-term.

Most beginners I work with report low energy in the first two weeks. This often stems from depleted B vitamins, magnesium, and electrolytes rather than the fasting itself. Supplementing strategically helps you avoid the rebound weight gain that happens when people quit too soon.

Core Vitamins and Minerals to Prioritize

Focus on these four daily while following a 16:8 or 18:6 intermittent fasting schedule:

Electrolytes and Timing Your Supplements

Electrolytes are non-negotiable. Sodium, potassium, and magnesium levels drop quickly when insulin decreases. I recommend 4,000–5,000 mg sodium, 1,000 mg potassium, and the magnesium listed above. Use salt in your water or take a zero-calorie electrolyte packet during your fasting window. Avoid taking fat-soluble vitamins like D on an empty stomach; consume them during your eating window to maximize absorption.

Keep it simple—no complicated meal plans. A high-protein meal with vegetables, healthy fats, and these supplements fits most busy schedules. Track your fasting blood glucose if managing diabetes; many see improvements within 4–6 weeks when nutrients are optimized.

Common Pitfalls and How to Avoid Them

Don't overload on supplements out of fear. Start with the basics above for 30 days. Over-supplementing can cause digestive issues that derail progress. If insurance won't cover programs, these affordable over-the-counter options cost less than $1 per day. Consistency beats perfection—pair this with gentle movement like walking to protect joints while rebuilding confidence.

Results from my community show an average 12–18 lb loss in the first 8 weeks when these vitamins support the metabolic repair that intermittent fasting triggers. Listen to your body, stay hydrated, and celebrate small wins to overcome past diet failures.

💬 What the Community Says

The community shows strong interest in vitamins during intermittent fasting, especially among those over 45 dealing with fatigue and hormonal issues. Most practitioners report magnesium and B vitamins as game-changers for energy and sleep, while Vitamin D is frequently praised for joint relief and blood sugar control. Electrolyte discussions dominate threads, with many sharing success using salt, potassium, and magnesium to prevent headaches and cramps in the first weeks. A vocal minority debates whether multivitamins are enough versus individual supplements, often citing past diet failures and skepticism about new regimens. Beginners commonly express embarrassment asking doctors and frustration with conflicting online advice, yet lived experiences highlight that simple routines lead to sustainable results when combined with realistic eating windows. Insurance concerns surface regularly, pushing people toward affordable drugstore options rather than expensive programs.
Cite this answer
Clark, R. (2026). What vitamins should I be taking while doing intermittent fasting. *CFP Weight Loss*. https://ask.cfpweightloss.com/ask/what-vitamins-should-i-be-taking-while-doing-intermittent
Russell Clark, FNP-C, APRN, FNP-C, APRN
About the Author

Russell Clark, FNP-C, APRN, is the founder of CFP Weight Loss in Nashville and CFP Fit Now telehealth. Over 35 years in healthcare — Army Nurse Reserves, Level 1 trauma ER, hospitalist — he developed a 30-week protocol integrating real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 30–90 pounds. He and his wife Anne-Marie lost a combined 275 pounds using the same protocol.

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