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by Christian Maino-Vieytes, B.S. Nutritional Sciences, University of Maryland, College Park, M.S. Candidate, Division of Nutritional Sciences, University of Illinois at Urbana-Champaign

Vitamin B12 represents an essential nutrient involved in energy metabolism. It forms what we in the field of nutrition call a co-enzyme­. It is a necessary component of certain enzymes, the miniscule proteins in our body responsible for carrying out all of the chemical reactions that keep us alive. Think of it as being analogous to a spark plug that allows a car to turn on and combust fuel. Without it, the car will not work.

We often hear about the dangers of developing a vitamin B12 deficiency from physicians, other providers, or the media. In fact, a B12 deficiency can be a very serious predicament. Knowledge about symptoms as well as how to prevent such a deficiency from occurring in the first place is crucial.

What are the sources of vitamin B12? 

A common misconception is that vitamin B12 originates in animal products. Nevertheless, just like us humans, other mammals that we consume need an exogenous source of B12 as well. Their cells and tissues cannot produce this critical vitamin. Vitamin B12 originates in the soil. Specifically, it is made by bacteria living in the soil that interact with various root systems. The animals that we consume for nutrition be it cow meat or poultry obtain their B12 by ingesting soil particles along with their normal feed. A long time ago, our primordial ancestors were likely getting their B12 through similar means. Needless to say, this method of soil consumption for obtaining B12 in today’s modern world seems a little impractical and outdated.

Given that other animals do the dirty work for us (no pun intended), we consume their meat and obtain a recycled form of B12 that is adequate. The majority of individuals rinse and clean their vegetables thoroughly before consumption. This aspect of modern life coupled with the fact that we drink from a purified source of water puts vegetarians and vegans at an increased risk of developing a vitamin B12 deficiency.

What happens during vitamin B12 Deficiency? 

Vitamin B12 is fundamental for the proper functioning of red blood cells, the nerve cells that make up your central nervous system, and for DNA production. Accordingly, the symptoms of deficiency relate to these systems and include:

  • Anemia
  • Mood swings that can lead to depression
  • Fatigue
  • Difficulty concentrating
  • Weakness
  • Mouth and tongue ulcers

Vitamin B12 Supplementation 

Medical authorities recommend that those who partake in vegetarian or vegan eating patterns take weekly or daily supplementation. Those in the elderly population are also at risk for deficiency. Nevertheless, a growing body of evidence suggests that B12 deficiency significantly affects omnivores as well and up to 20% of the population may have low vitamin B12 levels. Accordingly, many physicians and dietitians recommend that all individuals consume some form of supplemental B12, especially given that B12 toxicity is not very common and any excess is expelled through the urine. Most multivitamin supplements contain B12 as part of their formulations. In addition to animal products and supplementation, vitamin B12 can be found in many cereals and other products, such as Nutritional Yeast, that are fortified with this essential vitamin.


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