Vitamin B12 is a vital vitamin with a central role in our health. As an important coenzyme, it is used by all cells in our body and has an impact on building red blood cells, nerve protection, cell division, neurotransmitter synthesis, energy metabolism and especially protein metabolism. You can group the many effects into 5 main parts:B12 effects

Where to find B12

Vitamin B12 is not produced by plants, instead, it is produced by bacteria in the human and animal gut. So, theoretically we would not need to think about a proper supply but in reality, a deficiency can come very easy. You will find the highest concentration of this vitamin in the liver, meat and also some in dairy products. Chlorella or sauerkraut are known as a plant-based option. But according to a study from National Center for Biotechnology Information the amounts found in fermented vegetables (like sauerkraut) are rarely enough to provide a stable source for the daily requirement.


You have probably heard many times that vegetarians are the main target group for a deficiency. It is the most obvious conclusion because B12 is only to be found in animal products. In fact, most of the time a disorder of absorption is the problem.

  • To be absorbed B12 needs the help of the Intrinsic Factor. That´s a glycoprotein which is used for transportation purposes and is produced in the stomach. If there´s not enough Intrinsic Factor only small amounts of this vitamin can be absorbed by passive diffusion. For that reason inflammations in stomach and gut are the most common reason for a deficiency. Another important fact: the attachment to the Intrinsic Factor is dependent on calcium! If there is not enough calcium, vitamin b12 will be flushed out of your body unused.
  • Stress can also be a possible reason for a deficiency. Especially hormones like adrenalin and serotonin are much needed during busy times and therefore B12 is necessary as a building block. The more stress you are experiencing the more will your stores be emptied. And keep in mind that sports have the same effect on the body like negative stress on a busy day at the office.
  • Medication can result in a deficiency. For example, if you are taking medication against heartburn the excessive acid in your stomach will be reduced. At the same time, the resorption of B12 gets reduced too.

Food Sources

egg yolk 2 microgram per 100gr. 
mozzarella 1,7 microgram per 100gr. 
salmon 2,9 microgram per 100gr. 
emmental cheese 3,1 microgram per 100gr. 
salted herring 12,6 microgram per 100gr. 
oysters 15 microgram per 100gr. 
liver 60 microgram per 100gr. 


The daily dose of Vitamin B12 is 3 microgram.