As a runner, training and nutrition go hand in hand for optimal performance. But getting the right balance of every nutrient can be a challenge, even if you’re focusing on a balanced diet. Vitamin B12 is one nutrient that you may want to keep an eye on.
It’s involved in many functions in the body, and occasionally runners may have sub-optimal Vitamin B12 status.* Plant-based runners have a higher risk of deficiency, with one study finding that only 4 percent of omnivore runner participants were deficient in B12, while 11 percent of vegan runners were deficient.*
Not to worry, friends! As a dietitian, here are my top tips for why and how to get enough Vitamin B12.
Disclosure: This post is sponsored by NOW®. As always, all opinions are my own.
Disclaimer: This post has been written and reviewed by Chrissy Carroll, MPH, RD, RRCA Running Coach. It is for informational purposes only and should not be construed as individual nutrition advice. Consult an MD or RD prior to starting a new supplement regimen.
Functions of Vitamin B12
Vitamin B12 (also known as cobalamin) is a water-soluble vitamin. Here are some of the key functions of B12 for runners:
1. Energy Production*
Vitamin B12 is involved in the metabolism of carbohydrates and fats, helping convert these nutrients into energy.* Your body needs to be able to break down the foods you eat into this energy that can fuel your runs.*
2. Red Blood Cell Production*
Because Vitamin B12 is a cofactor in one of the steps of making red blood cells, it’s key that runners get enough.* Red blood cells help carry oxygen to your working muscles. Without adequate B12, you can develop a form of anemia (where you don’t have enough healthy red blood cells).*
Because of its role in healthy blood cells and energy, one of the primary symptoms of B12 deficiency is fatigue.* In athletes, this can mean reduced performance.*
3. Healthy Nervous System*
Vitamin B12 is essential for nervous system function.* It is involved in the production of myelin, a coating that surrounds parts of nerves.* That coating acts like insulation, ensuring the messages are transmitted fast from one nerve cell to another.*
When someone develops a Vitamin B12 deficiency, the NIH notes that they may have neurological symptoms like tingling, trouble walking, uncontrolled muscle movements, or confusion.* Obviously, none of these are ideal for a runner!
Recommended Intake
For men and women older than 19 years of age, the recommended intake each day is 2.4 micrograms per day.
However, even though there are ample food options that contain B12, research still shows that around 8 percent of females in the United States do not meet recommended dietary intakes. In addition, some people may eat a variety of food sources, but could have trouble absorbing B12.
Food Sources of Vitamin B12
Animal products are the best sources of Vitamin B12, which is why it can be difficult for people who don’t eat these products to meet their needs. There are a few plant-based products that may be fortified with B12 though.
Here are some good sources to include in your diet:
Animal Food Sources
- Beef
- Milk
- Pork
- Fish
- Shellfish
- Poultry
- Yogurt
- Cheese
- Eggs
Plant Food Sources
- Fortified cereals
- Fortified milk alternatives
- Fortified nutritional yeast (like NOW® Nutritional Yeast Flakes, which can be used to add a savory, cheesy-like flavor in vegan cooking)
Keep in mind the bioavailability of B12 from different foods can vary. For example, some studies have shown the bioavailability from dairy products is higher than that of other naturally occurring food sources.
When to Consider a Supplement
Supplements can be a nice way to ensure you’re meeting your needs. As an RD, there are generally three situations where I believe runners should consider a Vitamin B12 supplement:
- If your blood work has shown a Vitamin B12 deficiency*
- If you follow plant-based diet (especially strict vegan diets)*
- If you notice you don’t eat many B12-rich foods*
Keep in mind that deficiencies can happen even if you are eating a variety of B12-rich foods. Sometimes people don’t produce enough intrinsic factor, a compound made in the stomach that is essential for your body to absorb Vitamin B12 from food. Because of this, it’s a good idea to have your Vitamin B12 levels checked annually at your physical or if you are experiencing any symptoms of a deficiency.
(I speak from personal and professional experience on this – I ended up with a Vitamin B12 deficiency this year even though I regularly eat dairy products and meat!)
Even if you are not sure if you meet one of the three criteria above, it’s generally safe to take a Vitamin B12 supplement (either alone or as part of a multivitamin) if you just want to ensure that you’re meeting your needs.
Supplement Options
There are many different types of supplements on the market, like lozenges, oral tablets and capsules, sprays, and liquids. (In severe deficiencies, intramuscular injections are sometimes also used.) Recent research suggests similar effectiveness between these different routes of Vitamin B12 supplementation.*
If you’re looking for a supplement option, NOW® is my recommended brand of choice – not only because I work with them, but because I have seen the amount of testing and quality commitment that they put into their products. (In fact, each month they do over 19,000 tests on their products).
They offer several B12 options, and here are a few of my favorites:
- B-12 Lozenges (either 1000 mcg or 2000 mcg) – These are a great option when you need a simple B12 supplement to help meet your daily requirements. They’re easy to take; you can either hold them in your mouth until they dissolve or chew them and swallow.
- B-12 Liposomal Spray – This can be sprayed directly under your tongue, held for 20 seconds, then swallowed. It’s a great option if you hate pills or tablets, and each spray provides approximately 1000 mcg of Vitamin B12.
- Ultra B-12 Liquid – If you want to supplement with multiple B vitamins, this is a good option. It contains B12 along with the other seven B vitamins. You can take this liquid as a teaspoon in the morning, holding it in your mouth for about 30 seconds then swallow.
All three of these options are appropriate for someone on a vegan diet that does not eat animal products.
Fun fact: You can score 20% off any order on the NOW® website using code CHRISSY.
The Bottom Line
As a runner, it’s smart to put effort into the things we can control that impact performance. Think consistency in training, good recovery strategies, a balanced diet, and (when appropriate) choosing good supplements.
Considering Vitamin B12’s role in energy production, healthy blood cells, and a healthy nervous system, it’s a good idea to ensure you get enough in your diet and don’t have a deficiency.* If needed, take a quality Vitamin B12 supplement daily to help meet your needs.
A well-rounded approach to nutrition is key to unlocking your full running potential!*
*These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure or prevent any disease.
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