Take Your Vitamins? Supplements for Runners

Slack for iOS Upload (26)Some of the conversations about doping allegations in the lead-up to the Olympics involved the use of supplements by athletes who later tested positive for banned substances, such as swimmer Yulia Efimova. She received her first doping ban because it was found she took a supplement containing DHEA. She claimed she wasn’t aware that a product she purchased at GNC contained the banned substance. I’ll discuss the validity of her claim in a follow-up to this post later, but for now let’s assume she was telling the truth.

Her explanation seems so innocent from the outside because it’s something we have probably all done. You read a click-bait article or blog post about a super-fast runner who takes XYZ supplements. The next thing you know, you’re walking out of your local vitamin store with a bag full of pills and powders that you’re not sure what to do with and you’re not even sure what they contain, and a maxed-out credit card to boot. Aside from the pitch you got from the commission-based salesperson, information about supplement use is confusing, often anecdotal, and frequently contradictory.

How do you know which supplements may actually benefit your health or running performance, if any? How can you use them safely?

What exactly is a supplement, anyway?

In essence, supplements are vitamins, minerals, herbs, amino acids, or dietary substances which include common ones like calcium, fish oil, or whey protein. A good way to tell if a product is a food or a supplement is by reading the label. Where foods have “Nutrition Facts” on the back, supplements will have “Supplement Facts.” Supplements are not approved by the Food & Drug Administration (FDA), and this includes vitamins.  Lack of FDA regulation of supplements means that you need to carefully evaluate the veracity of the claims made by any supplement brand or proponent. The best thing we can do is try and be informed, stay relatively up to date, and take responsibility for what we put in our own bodies. 

Do you need a supplement?

Some things we experience on a run may tell us a supplement may be warranted. For example, fatigue and muscle cramps are potential signs of vitamin or mineral deficiencies. While one bad run is common, if these conditions occur on a regular basis, then it may be time to get blood work done by a medical professional to look for signs of these deficiencies. Start by keeping a log of any symptoms you may be having. This makes patterns more noticeable, and gives you a starting point when consulting your doctor.

But even if you determine that a nutritional deficiency exists, a supplement might not be the first option. For example, let’s say you’ve been tired, experiencing some muscle weakness on runs and have some joint pain as well. Your blood work shows that your Vitamin D levels are slightly low. What are the next steps?

  • Eat more foods that are naturally high in Vitamin D. There aren’t a ton of foods naturally high in this vitamin, but egg yolks, salmon and liver are great sources.
  • Incorporate food or drinks that are fortified with Vitamin D such as milk and orange juice.
  • Find out if there are other natural sources. Get some sunlight! 
Slack for iOS Upload (27)
Vitamin D levels often dip in the winter, but rise in the summer.

Natural ways of taking in vitamins are by far safer and healthier than supplements and often require nothing more than a few small changes to your diet or lifestyle.
However, sometimes your deficiency might be more severe, so a supplement may be necessary. Your doctor will work with you to create a treatment plan to specify how long you will need to take the supplement and likely suggest a specific type or even brand of supplement to take. 

For example, despite all my efforts to use diet and sunlight exposure to improve my levels, I need to take a Vitamin D supplement. Working with my doctor, I started supplementing in early fall when I’m not experiencing glorious summer sunny runs and know my levels will soon be dropping. This helps prevent a rapid drop in my mood and energy levels when winter arrives and my Vitamin D levels naturally go down. I continue to take the supplement through the winter and I wean myself off of the supplement as spring comes to an end and I get more natural sunlight. 

*** When you take any medications or supplements it’s important to know how they might react with any health issues or other medications you might be taking. This is why it’s important to talk to a doctor and do your research because contraindications can even be life-threatening, especially if you are pregnant. ***

Finding and Choosing Supplements

Once you have established a medical need for a supplement and need to search for a supplement, start your search by looking for trusted brands. To find trusted brands, look to third party testers like the US Pharmacopeial Convention (USP). The USP label on the bottle is a good sign that you are actually buying what the label on the bottle is selling. Getting suggested brands from your health care professional is another good option. Additionally, make sure you know what is in the supplement you are taking by reading the supplement facts on the back. If you’re buying a glucosamine supplement and there are a bunch of other things on there that you aren’t sure about, ask someone.

One Saltine discovered her multivitamin contained a laxative, after taking it regularly for over a year! That turned out to be an easy explanation for her poop problems on the run, but one that could have been avoided. So be sure to also check the back of your multivitamin for things like that, but also to see if it contains the vitamins or minerals that are in other supplements you take to be sure you aren’t taking much more of something than you need or in an amount that could hurt you.  

Evaluating Supplement Use

Your doctor may order repeat blood work in a few months to see if your levels have improved. It can take time to tell if something is working; supplements are not magic pills (and if they are marketed as such, run!). Additionally, continue keeping a log to document how you are feeling and note any side-effects. Some side-effects that might impact your running include GI distress, bloating, or constipation. If you are experiencing these symptoms, work with your doctor to determine if you can take it at a different time of day, with a meal, or if you should stop taking it all together. 


At the end of the day it all comes down to you. You don’t need to take something just because some pro athlete is or isn’t, and you don’t need to take something just because the internet told you to. In fact, you likely don’t need to take any supplements at all. We don’t all need to run the same amount of miles, use the same training plan, or follow the same diet, so supplements should be no different.

How do you decide which supplements you need? Which ones, if any, do you take?

A new mom and Upstate, NY resident who loves the marathon, a good beer, and all of the numbers/nerdy things. I write about my journey to a sub-3:00 marathon, training tweaks for improvement, and finding that "running/life balance" unicorn. On tap Next: Maneuvering through motherhood and postpartum running!

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.


  1. Whew! So much here, Barley! Generally, I agree that we should be skeptical of supplements without medical supervision. One thing I’ve found in my experience though, is that sometimes we as runners might be on the low-end of normal and a doctor will say it’s fine, but in our running we FEEL the effects of a mild deficiency. For instance, my ferritin was on the low end of normal and the doctor said it was fine, but I had all the symptoms of pre-anemia when running. After lots and lots of reading, I took a liquid iron supplement (well-timed during the day – clutch) and within 8 weeks was feeling much better!

    1. Oh I totally agree that as runners we probably tend to need a bit more of things (iron specifically) than non runners. But I still think that talking to doctor and bloodwork is usually a good starting point. If you are on the lower end of normal (what I am for Iron, like you), I still opted to take iron supplement as well as increase dietary iron. I think, my issue is when people take something without knowing if they need it- for instance a runner who starts taking iron because she THINKS it’s what she needs, only to find out her iron levels are actually too high (dangerous too!) and her symptoms were being caused by something else. I know that I am personally a numbers person but I think that bloodwork can provide hard data that gives people a better idea of where they are at and can go from there instead of blindly guessing

      1. Yes! I wouldn’t know any of the things about my levels without going to the doctor for the blood work! And I am very skeptical of supplements for all the reasons you mention: no oversight, so no guarantees you’re getting what the bottle says you’re getting, no guarantees the stuff will do what “they” say it will, and on and on and on. I just wanted to add that little point from my experience 🙂

  2. Really good article! I think that being a varsity athlete in university and going through the drug testing project made me very aware about being conscious about what you’re putting in your body – and the fact that not everything is as labelled. I know work in the area of drug regulation and it is crazy how many adulterated products are out there!