Understanding Cobalamin – Vitamin B12

Vitamin B12, also called Cobalamin, is vital for many body functions.

It is a critical vitamin for nerve and brain function, and for healthy synthesis of normal red blood corpuscles (red blood cells).

Lack of this vitamin can result in low energy, nerve symptoms and nerve pain. Some women experience painful periods or even lack of periods when this vitamin is deficient.

B12, often called ‘the red vitamin’, due to it containing the atom cobalt at its center, as well as carbon, oxygen, nitrogen and phosphorus.

So after reading many nutritional forums I am a part of, and discussing in clinic with my patients, I keep coming across the theory that all vegetarians and vegans will be deficient in this important vitamin.

Stated many times in the various nutrition text books I have studied over the years, this concept keeps bugging me, because I am a lifelong vegetarian and am not deficient in this vitamin as far as I am aware.

How is this possible? Animal foods are said to be the only consistent nutritional source of B12.  Bacteria in the intestines make B12 as a by-product, we know this is true, but not in sufficient quantity so if you don’t eat meat, and don’t take it regularly as a supplement, you will be deficient right?

Well that is not what I have found. I took it as a supplement probably 10-12 years ago when I was studying nutrition, and I am not suffering from B12 deficiency – so I decided to get it tested in a lab to see the results. I do not expect to still have it stored from supplementing with it more than a decade ago.

This blood test was done in December 2019, just took me a while to write this paper. 2020 has been a crazy year for everyone!!!

This is my personal medical report so I can share it, kind of interesting I think. Here it is below; I just blanked out some private information like my age. But in case you are wondering, I am 41 years old at the time of writing this paper.

So now we get to the interesting points. My levels are high, not low, and I am strictly vegetarian. In Australia we want the B12 levels in between 139-651. Mine came in at closer to the top end with 552.

You will get some B12 in the diet from animal sources like milk, cheese, yoghourt, and especially egg yolks if you are vegetarian, and from meat and especially organ meats if you are carnivorous. These vegetarian sources are generally not considered to be in high enough doses to carry out necessary body functions.

The B12 in these foods are from bacteria, not the foods themselves.

But even these foods are not thought to have sufficient quantities, so where is the B12 coming from? The answer is simply bacteria!

If your gut is strong and healthy, you will make all the B12 you need by nourishing your intestinal bacteria. You achieve this with plant foods and fermented foods like sauerkraut, kimchi, miso ect…

B12 is unique in that it is the only vitamin humans can make (or rather the gut bacteria makes). B12 has another interesting characteristic, in that it can be stored in the body for weeks or even months, possibly even years – mainly in the Liver.

This is very unusual as all B vitamins and vitamin C are said to be ‘water soluble’ which means we cannot store them in the body long term, so we need them often from our diet. B 12 is the exception to this.

Carnivores that lack B 12 usually have a genetic issue, or lack a glycoprotein (carb/protein complex) in the stomach called intrinsic factor that B12 needs to bind to for proper absorption.

Most B12 is absorbed in the last part of the small intestine, which is called the Ileum, and especially the last part of the Ileum.


  • Vegetarians and especially vegans are more prone to B12 deficiency, but this is easily overcome by improving the gut microbiome and health of gut bacteria.
  • Fermented foods are especially important to assist with gut health and B12 production.
  • Meat-eaters who are deficient in B12 are usually suffering from genetic reasons and issues with intrinsic factor.
  • Just because you are vegetarian or vegan, this does not mean you will be deficient in B12, unless your gut is not working properly.

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