8 Supplements That Are Breaking Your Fast | AVOID These!

Intermittent Fasting means alternating between fasting windows during which you avoid eating food, but what about your supplements and vitamins? Will they break your fast? This post shares which vitamins and supplements will affect your fast, and which are safe to take. Plus: Intermittent Fasting FAQs on medicine and supplements!

If you’re reading this, you’re probably already experimenting with an Intermittent Fasting (IF) lifestyle, or seriously considering it. Well, I’M ALL FOR IT for a few of these reasons…

Intermittent Fasting can…

As I discuss in my Beginner’s Guide to Intermittent Fasting for Weight Loss, IF involves intentional periods of eating (called your eating window) and of refraining from any food (called your fasting window).

During your fasting window, you’ll want to stay away from any food or drink that contains calories, with a few exceptions, to allow your body time to go through autophagy (which is when your cells work, doing things like removing old proteins). During fasting, your body also sees an improvement in blood sugar levels because of better insulin sensitivity. Studies show that intermittent fasting improves insulin response, helps you lose weight, and does the good things I mentioned above.

But, what about supplements during your fasting window? Will supplements break your fast? Interestingly enough, some supplements may even benefit your fast on an empty stomach, while others will most certainly break it. 

So, let’s break it down, and understand what you can safely take during your fast and what to avoid for a truly successful and effective IF journey. 

Let’s get started!

Do Vitamins Break A Fast?

What’s The Difference Between Vitamins and Supplements?

The main difference between vitamins and supplements is that vitamins are naturally-occurring nutrients in our body, whereas supplements are naturally-occurring or synthetic chemicals taken as a complement or “supplement” to your diet. Additionally, vitamins include vitamins A, B, C, D, E, and K while supplements contain multiple ingredients, such as multivitamins and dietary minerals.

Vitamin A
B Vitamins (Thiamin, Roboflavin, Niacin, Folic Acid, etc.)
Vitamin C
Vitamin D
Vitamin E
Vitamin K
Vitamins (Multivitamins)
Minerals (Calcium, Magnesium, Iron, etc.)
Botanical Compounds (Caffeine, Curcumin, etc.)
Botanicals or Herbs (Echinacea, Ginger, etc.)
Amino Acids (Tryptophan, Glutamine, etc.)
Live Microbials (Probiotics)


As you can see in the above table, Vitamins can be a type of Supplement when taken as part of the diet and different from conventional food, though Supplements cover a more broad classification of products intended to treat, diagnose, cure, and/or precent disease, and are taken in many forms, including tablets, capsules, soft gels, gel caps, powders, bars, gummies, and liquids.


Vitamins, on the other hand, are a group of substances that are essential for normal cell function, growth, and development. There are 13 essential vitamins, and each of them is required for the body to work properly.

What Are The Two Types Of Vitamins?

Vitamins are divided into two categories. These are:

  1. Fat-Soluble Vitamins: These types of vitamins are stored in the body’s liver, fatty tissue, and muscle. Included in this category are: Vitamin A, D, E, and K. These should be taken with foods containing fat for your body to better absorb them.
  2. Water-Soluble Vitamins: There are nine of these type of vitamins, which includes Vitamin C and all the B vitamins. These vitamins aren’t stored in your body. Any leftover or excess amounts of these leave the body through the urine. Water-Soluble Vitamins have to be consumed on a regular basis to prevent shortages or deficiencies in the body (except for Vitamin B12, which can be stored in the liver for many years).
Do Vitamins Break a Fast (800 × 1200 px)

Now that we understand the difference between vitamins and supplements, and the different types of each, let’s discuss which vitamins and/or supplements will break a fast.

Will taking vitamins break my fast?

Short answer: No, vitamins do not break your fast. 

Vitamins will not break a fast as long as you’re consuming the right kind of vitamins. Many vitamins and supplements contain small amounts of carbs, sugar, fillers or additives — which will break a fast. For vitamins, that primarily means gummy vitamins will bring you out of a fasted state because of the caloric value and sugar content.

However, like we discussed earlier, fat-soluble vitamins should be taken with foods containing fat to be better absorbed by your body, which means they should be taken during your feeding window for better absorption. This also means water-soluble vitamins will not break your fast, and are fine to take on an empty stomach, and while fasting.

Vitamins/Supplements That WILL NOT Break A Fast
Water-Soluble Vitamins
Multivitamins (That Do Not Contain Sugar, Carbs, Additives and/or Preservatives )

What Supplements Will Break A Fast?

Like we’ve mentioned, during a fasting period, you should avoid any foods, including supplements, that have a high energy intake (meaning contains calories). This is almost entirely true is your purpose for fasting is for weight loss, body recomposition, and/or improved insulin resistance, though certain foods that do contain calories (like bone broth or collagen) could not break a fast if your goal is a bone broth fast, which is outside the scope of this article.

Vitamins/Supplements That WILL Break A Fast

The following supplements shouldn’t be consumed during your fasting window:

  • Protein Powders: Many protein powders contain 15+ grams protein, 5+ grams carbs, and at least 100 calories, which will certainly break a fast. The purpose of a protein supplement is typically to build muscle and to allow your muscle recovery after a workout, which requires energy (AKA calories).
  • Gummy Vitamins/Supplements: Gummy supplements are often made with added sugars, additives, and calories, which will break a fast.
  • Fat-Soluble Vitamins: While a fat-soluble vitamin will not technically break our fast, it is important to consume fat-soluble vitamins with food that contains fat so that is can better be absorbed by your body, which makes it not a good option for during a fast.
  • Bone Broth: This one is a little tricky. In short, yes, bone broth contains between 30-50 calories per cup, and will break your fast. BUT even if the fast is broken, the goal of intermittent fasting is usually to put your body into a fat-burning state, and bone broth can help with this during a longer fast, which is why some say it’s okay to drink in a fed or fasting state. Personally, we consider a fast-breaker, and avoid it when fasting unless completing a bone broth fast.
  • Collagen: Collagen contains approximately 30 calories per serving, and will break your fast. Like bone broth, while collagen does technically break a fast, it is still allowed under many IF plans due to its low-calorie profile. Also like bone broth, we prefer to leave it to feeding windows.
  • MCT Oil: While MCT oil does contain calories, it is absorbed differently than other types of fat. Additionally, MCT oil doesn’t stimulate insulin production in the body, which means that it shouldn’t impact the body’s fat-burning capabilities. MCT Oil is a high-calorie food that will break your fast, though it will not directly disrupt the health benefits of intermittent fasting.  We consider it a fast-breaker.
  • Branched-Chain Amino Acid (BCAAs):  A full dose BCAA supplement contains about 4g of BCAA, so a serving would make up about 20 calories in total. Many take BCAAs to prevent muscle loss during a fast, though it is technically ending your fast when you take them because they contain calories. If you’re strictly fasting, we recommend avoiding BCAA supplements in your fasted state.
Vitamins/Supplements That WILL Break A Fast
Fat-Soluble Vitamins
Branched-Chain Amino Acids (BCAAs)
Gummy Vitamins
Protein Powders
Bone Broth
Multivitamins Containing Sugar, Carbs, Additives and/or Preservatives

If you want to learn more about what you can have during your fast, check out my Beginner’s Guide to Intermittent Fasting.

Do Gummy Vitamins Break a Fast?

Since gummy vitamins usually contain sugar and protein, they’re likely to break your fast. What’s more, they’re usually sweet which can trigger a hunger craving and that wouldn’t be ideal for you. So if you’re on IF, taking these during your eating window would be your best bet for a successful fast. Additionally, we recommend reconsidering gummy vitamins in general, given their added sugar.

Does Medication Break Intermittent Fasting?

As long as it’s free from calories and ingredients that can break your fast, medication shouldn’t interfere with IF. HOWEVER, the safer question to consider would be how you can schedule your fast around your meds instead

You might be taking meds that require food while some should be taken during your fast. Luckily, IF is flexible so you can always choose a schedule that suits you

It’s always best to prioritize your medication or supplement routine as prescribed by your doctor or healthcare provider. If you’re on maintenance meds, it’s also best to consult them before doing IF.

Do Vitamins Break A Fast?

More Helpful Posts On Intermittent Fasting

Looking to level up your IF game? Here’s all I’ve learned throughout my journey: 

This post contains affiliate links for products I use regularly and highly recommend.

Lacey Baier

Hey y’all, I’m Lacey Baier and I’m so glad you’re here! I’m a healthy lifestyle influencer and the creator of this clean-eating blog and YouTube channel, A Sweet Pea Chef. My recipes have been published on Food Network, Good Morning America, FoxNews, Tastemade, Fitness Magazine, and much more. I live in Dallas, Texas with my husband and four kiddos. Let’s get started!

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