Fasting is something that people have been doing for centuries. Our ancestors practiced fasting during periods of food scarcity, but they also practiced intermittent fasting during periods of abundance, as the food they consumed was much more nutrient-dense than what we consume today, meaning it sustained them for substantially longer periods than the carb-rich meals we typically eat. While fasting has been practiced for hundreds, if not thousands of years in several different religions, the fasting we do today is typically promoted for its long list of health benefits.

Be it increased energy production and better athletic performance, or enhanced detoxification and sharper brain function, the benefits of abstaining from food span far beyond weight loss. So, we’re breaking it down for you. We’re talking about what fasting is and why people do it, how supplements can still be a part of a fasting protocol, and what’s safe to take and what’s not during a fast. Let’s get to it.

Best 6 Vitamins To Take During Fast

Electrolytes (sodium, magnesium, potassium)

Electrolytes like sodium, potassium, magnesium, and calcium are required for several key body processes, including muscle contraction, fluid balance, nerve conduction, and more. If you’re training in a fasted state, electrolytes are lost through sweat, but imbalances in minerals can also lead to feeling lightheaded or dizzy.

As well, because fasting often involves drinking large amounts of water to maintain hydration, you want to ensure you’re balancing that out by adding minerals back in. Whether it’s in the form of an unsweetened pure electrolyte beverage or purchasing powdered versions of the minerals, find a way to get them in during your fast. Magnesium is a common deficiency for a lot of people and plays a role in more than 300 biochemical processes in your body that regulate energy production, muscle function, bone growth, protein synthesis, and more 3.

And because a magnesium deficiency can affect calcium and potassium levels in the bloodstream, you can start to experience things like muscle cramps, fatigue, irregular heartbeat, digestive symptoms, and weakness. Sodium and potassium also play key roles in muscle and nerve function, energy production, and regulating blood pressure and volume. Electrolytes do not contain calories, which means they don’t stimulate pro-growth pathways like mTOR, which is activated by carbs or insulin, and branched-chain amino acids, so they should be safe to consume during a fast—assuming they’re in the pure form.

Water-soluble vitamins (B-complex + vitamin C)

For the most part, any pure forms of nutrients will not disrupt ketosis or break a fast, and the same is true for the B vitamins and vitamin C.

The B vitamins are a group of 8 water-soluble vitamins that play a major role in energy production, metabolism, hematopoiesis (blood cell formation), cognition, nerve function, hormone balance, and much more 4. They also play a major role in supporting cellular functioning, as they act as co-enzymes in a wide array of catabolic and anabolic enzymatic reactions. Vitamin C, on the other hand, is a vitamin essential for proper immune function contributing to the cellular function of both the innate and adaptive immune system 5. It also acts as a powerful antioxidant alongside vitamin E to protect cells against oxidative stress.

Creatine

Creatine is a staple for a lot of athletes due to its role in muscle growth and energy production, and it’s one that’s safe during your fast. If you’re training during your fast, creatine can help increase energy supply through enhanced generation of ATP. The body uses creatine phosphate stores during high-intensity activity, such as lifting, jumping, and sprinting, but adding in creatine can help to support maximum physical effort since your body cannot depend on the breakdown of carbohydrates to provide energy in a fasted state.

As such, having more creatine phosphate in muscle tissue means faster ATP generation, which can result in greater gains in strength, power, speed, and muscle growth—even during fasting or caloric restriction. And because creatine is free of calories and does not contain anything that will trigger an insulin response, it will maintain a fasted state 6.

Iron

Iron is a supplement that isn’t common to a lot of people’s supplement stack because most people obtain sufficient amounts through diet, but if you’re someone who struggles with low iron stores or are a menstruating female, you’re in the clear to take your supplement during a fast. Because iron is best absorbed on an empty stomach in combination with vitamin C, take it during periods of fasting or before meals. However, some people can experience minor digestive upset, cramps, or constipation, and if you find this to be the case, consume your iron supplement with your first meal of the day during your feeding window.

L-tyrosine

If you want to avoid some of the fogginess that can come with fasting, L-tyrosine is a good one to add to your fasting stack. It’s an amino acid that’s your brain converts into three important neurotransmitters that play a critical role in the stress response and mood:

• Dopamine: Plays a major regulatory role in mood and is involved with the reward center of the brain.
• Norepinephrine: Supports the body’s stress response and muscle recovery.
• Epinephrine: Plays a role in motivation and focus.

While L-tyrosine is technically an amino acid and amino acids can break a fast, taken in low doses, it shouldn’t elicit any sort of response.

Probiotics and prebiotics

These guys are a necessity for supporting good gut health and everything that stems from a healthy microbiome, and they get the thumbs up for taking during a fast. Some bacterial strains are designed to be taken on an empty stomach when stomach acid levels are low and won’t interfere with function, however, check the label on your supplement to be sure.

Final Thoughts

Long story short, several supplements are okay to take during a fast, but you have to pick and choose what works and what doesn’t.

If the ingredients are anything but a pure vitamin or mineral, chances are it’s better kept for your feeding window to avoid stopping autophagy and kicking you out of your fast.