| Food & Diet

Can You Take Supplements While Intermittent Fasting?

By Christopher Walker

Can You Take Supplements While Intermittent Fasting?

Intermittent fasting is well known for its ability to blast fat, stimulate cellular repair, and prevent early signs of aging. With such a long list of health benefits, it’s easy to see why intermittent fasting has become such a popular health trend. For die-hard fasters, however, the health benefits don’t stop there. As dieters strive to take their fasts to new heights, it leaves many to beg the question: Can I take supplements while intermittent fasting?


  • Does Fasting Impact Nutrient Levels?
  • When to Take Supplements During a Fast
  • Best Supplements for Intermittent Fasting
  • Warnings
  • Does Fasting Impact Nutrient Levels?

    Essential vitamins and nutrients are required for survival. When the body goes through periods of starvation (fasting), naturally there is a loss of nutrients. Some of this loss is due to the body’s reliance on stored nutrients in the absence of food nutrients, some are lost during exercise and others are lost as fasting causes the body increasingly release water through urination.1 The amount of nutrient loss increases with the duration of the fasting period. Of the nutrients lost during fasting, electrolytes are amongst the first to go. To improve the likelihood of a successful fast, supplementation may be necessary to make up for these lost nutrients.

    Can I Take Supplements While Intermittent Fasting?

    In short, yes. In addition to making up for lost nutrients, certain supplements can also help with exercise recovery and cellular function while fasting. Although they can be beneficial, there is no universal method for taking supplements while intermittent fasting. Variables like your fasting schedule, diet and exercise all have an impact on the effectiveness and necessity of supplements.

    When to Take Supplements During a Fast

    Some supplements can cause nausea and discomfort when taken on an empty stomach so it’s a good idea to structure them properly in your fasting cycle. If you’re sticking to strict fasting periods with zero caloric intake, then scheduling your supplements during your eating windows can help you ensure you get the proper nutrients without breaking your fast before you’re ready.

    RELATED: 25 Supplements To Take While Intermittent Fasting

    On the other hand, taking supplements early in the day with something like coffee or tea can help you recover better from workouts and avoid symptoms of the “keto flu.” Depending on the method of intermittent fasting you use, you may need to experiment with your supplements schedule to see what works best for you.

    Best Supplements for Intermittent Fasting

    For a full list of the most popular supplements and nutrients to consume while intermittent fasting, visit our recent post here.


    One major group of nutrients lost during both intermittent and extended fasts are electrolytes. When you’re in a fasted state, ketone levels in your body rise, causing insulin levels to drop and essential nutrients to be flushed from the body. Electrolytes, which include sodium, magnesium, chloride, phosphate, potassium, calcium and bicarbonate, are essential to a number of bodily functions including the nervous and muscular systems. Electrolytes are also essential for ketogenesis, the process of converting fat into energy.  

    Depending on the type(s) of electrolytes you’re missing, the symptoms of electrolyte deficiency can vary. These symptoms include:

    • Nausea
    • Fatigue
    • Vomiting
    • Muscle Weakness/Spasms
    • Headaches
    • Irregular Heartbeat

    The symptoms of low electrolytes can make it quite difficult to make it through your fasting period. The best way to avoid an electrolyte imbalance and the symptoms that follow is to ensure you’re providing your body with the proper amounts of these essential nutrients while fasting. The most important electrolytes to supplement while intermittent fasting are potassium, sodium and magnesium. Potassium magnesium, and sodium, which are readily excreted from the body when in a fasted state, are vital to balancing fluids in the body and regulating blood pressure.2

    B-Complex Vitamins 

    B complex vitamins refer to a group of water-soluble nutrients essential to maintaining optimal health. These vitamins include:

    Thiamine: Thiamine, also known as B1 is essential to glucose metabolism. Thiamine helps the body break down carbohydrates and convert them into energy.

    Riboflavin: Riboflavin (or B2) is also essential to metabolism. Riboflavin also helps with cellular functions and helps maintain normal levels of amino acids in the blood. Prolonged riboflavin
    deficiency can result in weakness/fatigue and lead to anemia.

    Niacin: Niacin or, nicotinic acid is essential to the production of NAD and NADP, two enzymes that aid in cellular metabolic processes. Niacin also has antioxidant properties and is used by physicians to help lower cholesterol.

    Pantothenic Acid: Similar to niacin, pantothenic acid is needed for the body to produce coenzyme A (CoA), which is responsible for a number of chemical reactions in the body.

    Biotin: Biotin, also known as B7, is most known for its impact on the health of skin, hair, and nails. Biotin deficiency is usually identified by thinning hair, fatigue, and hallucinations.

    Folate: Your body needs folate to make red blood cells. Folate is essential to proper cellular functions and helps prevent harmful changes to DNA.

    B complex supplements combine all these nutrients into one. Because these vitamins are water-soluble, much like electrolytes, they are excreted from the body during fasting. In addition to their unique functions, B vitamins help the body break down nutrients, fats, proteins, and carbohydrates. Without these essential nutrients, your body can’t metabolize properly.

    Vitamin D

    Although extended fasting poses more of a risk for vitamin D deficiency, it’s still something intermittent fasters should pay attention to. Vitamin D is essential to immune health and also helps the body absorb other essential nutrients like magnesium.3


    BHBs, or Beta Hydroxybutyrate, is a way to provide your body with additional ketones, which are needed to convert fat into energy. BHB is one of three types of ketones naturally produced in the body. These supplements help ensure there are enough ketones in the bloodstream to metabolize stored fat as energy. BHBs are seen as a way to supercharge the benefits of intermittent fasting and ensure you are burning fat while in a fasted state.  


    If your nutrition plan includes exercising during your fasting periods, then you can benefit from BCAA supplements. BCAA or branched chain amino acids which perform the same as amino acids provided by protein, allow the body to build and maintain muscle. The fear of muscle loss while fasting has made BCAAs a popular supplement amongst fasters. Although they can be effective, BCAAs don’t come without their risks. Because BCAAs are caloric, they can potentially disrupt your fast. If you’re looking to stick to a strict zero-calorie fast, then these might not be the supplements for you.


    More than any other nutrient, one of the most prominent risks of fasting, both extended and intermittent, is dehydration. All of the body’s processes rely on proper hydration and this essential nutrient becomes even more vital when fasting. Dehydration causes dizziness, fatigue, cravings, and irritability, and can make it nearly impossible to make it through your fast. To give yourself the best chance at successfully completing your fast, make sure you’re drinking plenty of water.


    While paying attention to your nutrient intake is a great habit, you should be cautious not to overdo it when it comes to supplements. Although certain supplements can be beneficial, taking too many supplements can be dangerous. Overloading the body with too many supplements can cause nausea, dizziness, vomiting and can even lead to liver damage.

    Supplementation is more of a requirement for longer fasting periods (like five days). Although intermittent fasting may impact nutrient levels, it often isn’t enough to make you deficient. If you’re fasting windows only last about 16 hours, then its unlikely you’ll experience any major nutrient deficiency The truth is, abstaining from food and nutrients for short periods of time can spark a bodily process known as hormesis, which causes your body to use nutrients more efficiently in reaction to their absence.4 With everything considered, knowing which nutrients are at higher risk of deficiency and their symptoms can help you better manage your health and nutrition while fasting.

    Citations and Sources

    Fukuwatari T, Yoshida E, Takahashi K, Shibata K. Effect of fasting on the urinary excretion of water-soluble vitamins in humans and rats. J Nutr Sci Vitaminol (Tokyo). 2010;56(1):19-26. [PubMed]
    Magnesium Fact Sheet for Healthcare Professonals. National Institute of Health. https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/. Published September 18, 2018. Accessed January 22, 2019.
    Ross A, Manson J, Abrams S, et al. The 2011 Report on Dietary Reference Intakes for Calcium and Vitamin D from the Institute of Medicine: What Clinicians Need to Know. J Clin Endocrinol Metab. 2010;96(1):53-58. [PMC]
    Mattson M. Hormesis Defined. Ageing Res Rev. 2007;7(1):1-7. [PMC]