What Is Vitamin B12

Vitamin B12 an essential water-soluble vitamin that our body cannot make and should be consumed in appropriate quantities on a regular basis.

Why is it so Important?

Vitamin B12 does a lot of things for the body. It helps make DNA and red blood cells. Not to mention that Vitamin B12 provides energy for everyday functions. Since it plays a role in energy production, it is also crucial that runners get enough Vitamin B12 in their diet.

B12 is an important vitamin for everyone but particularly runners due to its role in the formation of oxygen-carrying red blood cells. Lack of B12 can lead to a condition called pernicious anemia, meaning that your body is producing large, immature red blood cells that don’t function properly. Without the proper amount of functioning red blood cells, your tissues can not receive all the oxygen that they need- think poor performance.

According to Harvard Medical School, a deficiency of Vitamin B12 in the diet can lead to a variety of problems, including anemia, weakness, fatigue, and memory loss.

Where can I get Vitamin B12?

Vitamin B12 is made by microorganisms in the animal’s intestines or diet, but humans are not able to make their own Vitamin B12.

Plants are not able to make Vitamin B12, which is why you will not find much Vitamin B12 in vegan foods. Because of this, many vegans choose to consume foods that are fortified with B12 or take a supplement.

Most respected sources place great emphasis on supplementing a vegan diet with adequate B12 sources. The Vegetarian Resource Group suggests that vegans need to have reliable sources of vitamin B12 in their diets. The Vegetarian Nutrition Dietetic Practice Group (VNDPG) of the Academy of Nutrition and Dietetics says that all vegans should include a reliable B12 source in their diets, such as fortified foods or supplements.

According to the Vegan Society to get the full benefit of a vegan diet, vegans should do one of the following:

  1. Eat fortified foods two or three times a day to get at least three micrograms (mcg or µg) of B12 a day
  2. OR Take one B12 supplement daily providing at least 10 micrograms
  3. OR Take a weekly B12 supplement providing at least 2000 micrograms.

According to the VNDPG recommends that all vegans should take 250 mcg per day of a B12 supplement.

Since B12 is a water-soluble vitamin, it never hurts to add more Vitamin B12-rich foods to your diet. Below is a list of plant-based foods to consider.

Vegan Food Sources with Vitamin B12


Vegan meat alternatives some are fortified with B12, but they usually also contain all sorts of artificial additives and therefore I don’t really recommend that as a source of vitamin B-12


The most convenient, least expensive and reliable option by far is: taking Vitamin B12 supplements. You can also ensure you’re getting enough B12 as a vegan by regularly consuming fortified foods like plant-based milk, cereal, tempeh, algae, shittake mushrooms, or nutritional yeast in addition.

Carol Aguirre MS, RD/LDN