6 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?

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 micronutrients we get from food, whereas nutritional supplements are to “supplement” your diet, giving you essential nutrients that you may miss if you don’t have a diet complete in all essentials.

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.)
Enzymes (Lipase,Papain, 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. They 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.

Supplements cover a more broad classification of products and are taken in many forms, including tablets, capsules, soft gels, gel caps, powders, bars, gummies, and liquids.

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 Vitamins 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. Excess amounts of these vitamins are excreted from the body through the urine. Water-Soluble Vitamins have to be consumed regularly to prevent deficiencies (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 Or Supplements Break My Fast?

This answer is not always black or white. I say that because in general, supplements that cause an insulin response or that have any calories at all may break your fast. The first thing that comes to mind for me is gummy vitamins. They’ll often contain gelatin, collagen, artificial sweeteners, or sugar which definitely stop ketosis and autophagy.

Any supplements with a coating can also break your fast as again, they can make changes to your insulin levels.

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 a fast and are fine to take on an empty stomach, and while fasting. But it’s important to note that sometimes b-complex vitamins can cause nausea if you take them on an empty stomach.

Vitamins/Supplements That WILL NOT Break A Fast
Water-Soluble Vitamins
Multivitamins (That Do Not Contain Sugar, Carbs, Additives, and/or Preservatives )
Probiotics (As long as they are non-caloric)

Do Supplements Ruin Intermittent Fasting?

Some supplements are not ideal to take when fasting.

As 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 if your purpose for fasting is for weight loss, body recomposition, and/or improved insulin resistance.

Let’s dig a little deeper below.

Vitamins/Supplements That WILL Break A Fast

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

  • Protein Powders: Per serving, most protein powders contain about 100 calories, more than 15 grams of protein and 5 grams of carbs. Anything that contains calories will break a fast. A protein supplement is typically used to build muscle and to allow muscle recovery after a workout. I often enjoy a protein smoothie after a workout!
  • Gummy Vitamins/Supplements: Gummy supplements (see my post on ACV gummies) are often made with added sugars, additives like collagen and gelatin, and calories, which will break a fast. If supplements have a coating or additives, this will break a fast too. Look for cane sugar, maltodextrin, and pectin for examole.
  • 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, I 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, I prefer to leave it to feeding windows.
  • MCT Oil: While MCT oil (coconut oil is high in MCTs) does contain calories, it is absorbed differently than other types of fat. 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. Studies also show that BCAAs trigger an insulin response. If you’re strictly fasting, we recommend avoiding BCAA supplements in your fasted state.
Vitamins/Supplements That WILL Break A Fast
Protein Powders
Gummy Vitamins/Coated Supplements
Bone Broth
Branched-Chain Amino Acids (BCAAs)

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

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 your doctor before doing IF.

Should I Take Multivitamins Or Supplements If I’m Fasting?

Yes, I think it is a good idea to take multivitamins or supplements when fasting but why not include them in your eating window to ensure there is no interruption in your fasted state? It’s important to make sure you are keeping your nutritional requirements at optimal levels. While I do feel that getting your nutrition through food is ALWAYS best, you can add these to your diet.:

Electrolytes like potassium, sodium and magnesium: These will help avoid muscle cramps, digestive issues, and lightheadedness. Magnesium for example, also helps muscle function.

L-tyrosine: I like this one because l-tyrosine helps with fogginess, mood and stress by converting to dopamine, norepinephrine, and adrenaline.

Important note: Chromium and vanadium can drop your blood glucose levels quickly and lead to hypoglycemia when fasting, so I’d advise against them.

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 there! I’m Lacey Baier and I’d like to welcome you! I’m a healthy lifestyle influencer and the creator of this clean-eating blog and YouTube channel, as well as cleanish, my clean-eating supplement brand. My recipes have been published on Food Network, Good Morning America, FoxNews, Tastemade, Fitness Magazine, and much more. I live in Austin, Texas with my husband and four kiddos. Let’s get started!

5 thoughts on “6 Supplements That Are Breaking Your Fast | AVOID These!

  1. Thanks so much. My vit D contains MCT oil and I was taking it after brushing my teeth. I also consume Activatedyou morning complete. Does that break the fast?

  2. Can I eat, anything at all, so that I can take meds and not break my 16 hr fast?? I can’t take them on an empty stomach???

  3. Enjoyed your article on vitamins and fasting. I have been fighting pancreatic cancer for seven years. Had the Whipple procedure done at that time. Have been using autophogy every day since then. I only eats thousand calories a day every 24 hours some times I fast for for four days. Followed this plan for those past seven years and my tests every 6 months since then have been no reacurance of cancer have been found. I have been walking 3 a half miles an hour since then also. Try to lift weights when I feel like it and also in the evening another 3 and half miles again in an hour. I eat only eat after fasting chicken, beef, or fish. Small baked potato occasionally with a little butter salt and pepper. Small amount of guacamole, occasionally red beans, my portions at dinner are mostly protein some carbs very little as carbs turn to sugar. a small portion of re beans. Cut out all sugars as cancer loves sugar. My weight as gone from 227 to 160 in those seven years. I only drink black coffee only or tea with lemon no sugar. Then throughout the day I drink water I try to drink 128 ounces daily. For the last 7 years I ve followed this process. I ve lived approximately 6 years longer than expected after the Whipple procedure for pancreatic cancer. Will continue to fight cancer this way until I passs

  4. Hi Lacey! Thank you for a great article! Do you have a particular form or brand of L-tyrosine that you would recommend?

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