Vegan Vitamin B12

B12 Supplements Vegans 

Vegan Vitamin B12

Is a natural vegan supply of vitamin B12 possible? Do plants contain B12? Can our body’s bacteria produce the vitamin? Should vegans take B12 supplements?

Vitamin B12 and the Vegan Diet

Vitamin B12 is an essential vitamin and without it health cannot be maintained. It is produced by microorganisms and is found almost exclusively in animal products. Because of this, vegans and vegetarians often struggle to obtain sufficient levels of B12 in their diet. 

Is it possible to consume sufficient B12 as a vegan? This article aims to answer this controversial question.

Is Vitamin B12 Vegan?

Vitamin B12 is not actually an animal product itself. It is produced by microorganisms found in a number of places: soil, water-based algae, the digestive tract of animals and also the human digestive tract.

Although vitamin B12 itself is vegan, it is rarely found in vegan friendly foods. 

Vitamin B12 and Vegan Food Products

Vitamin B12 can also be found in traces known as micro-bacterial contamination on the surface of some vegetables, especially at the root. But these traces are usually so small that they are barely noticeable. Additionally, the B12 content can vary according to factors such as location, soil quality and type of microorganism present; meaning that vitamin B12 from this source is too rare, unreliable and too low in content to be relied upon as a vegan supply. 

Moreover, in modern times the soil flora is usually destroyed by industrial agriculture, so that those vegetables that might have previously possessed some vitamin B12 are now extremely unlikely to.

Vegan Vitamin B12 From Oral Bacteria

Even in the human body, vitamin B12 producing microorganisms can be found along practically the entire length of the digestive tract. The majority of these are found in the large intestine, where they produce quite significant amounts of B12. Unfortunately our bodies are unable to utilize this, as B12 can only be absorbed in the small intestine. In this way, faeces contain a considerable vitamin B12 content – but this is not available to the body.

Despite this, a 1980 study published in the prestigious Nature magazine indicated that even the small intestine is able to produce significant amounts of vitamin B12.1 The same can possibly be said for the mouth and the throat. The is likely to be the reason why approximately 10 – 40% of vegans that were examined exhibited no signs of a vitamin B12 deficiency, despite their diet containing almost none.2

However, to rely on this provision of vitamin B12 would be careless. Several studies have shown that between 60 and 90% of vegans are suffering from vitamin B12 deficiency. The risk here is clear and should not be underestimated.3-4

Vegan B12 Health and Nutrition

It is particularly difficult to obtain a vegan B12 supply in today’s world due to some general health factors:

  1. The bacteria requires a neutral to slightly acidic environment. Industrialized countries today have an increasingly high frequency of acidic foods, which can easily disturb the microbiological equilibrium of our digestive systems.
  2. Many people suffer from bacterial overgrowth in the intestine. On the one hand this prevents the growth of probiotics (good bacteria). On the other hand it is also shown to increases the production of vitamin B12 analogs that prevent the absorption of genuine B12.5
  3. The increase of extreme hygiene has meant that the likelihood of coming into contact with the relevant microorganisms is highly unlikely. Our ancestors and animals would have obtained B12 from traces found in soil contaminating berries, but this is no longer the case. 
  4. In order to produce B12, the bacteria require the trace element cobalt. For many years now the cobalt content in humus has been decreasing.

These factors are likely to be the reason why our bodies can no longer self produce vitamin B12.

Vitamin B12 in Animals

The animal relationship with vitamin B12 is not quite the same as it is with humans. Ruminants such as cows are able to self produce sufficient quantities of B12 in their special stomach, the rumen. Other non ruminant animals unintentionally consume microorganisms, insects, soil, faecal matter and other vitamin B12 as they graze, something that the modern lifestyle has no place for.

This explains why animals that are herbivores do not require other sources of vitamin B12, unlike most vegans living in the western world. However, such animals living in captivity or on farms are often given B12 or cobalt supplements, because there is no longer a natural source available.

Providing Vitamin B12 for Vegans

In our research for this website we tested a number of vegans for vitamin B12 deficiency and remarkably we found that some exhibited no signs of a problem. They had some astonishing similarities:


  1. were on a totally or mostly raw food diet
  2. grew a proportion of their food themselves
  3. lived in a very health conscious manner, and had a history of detoxing and fasting
  4. led a spiritual life, practiced yoga, meditation and similar activities likely to contribute to low stress levels

Theses: Vitamin B12 for Vegans

These observations do not claim to be scientific as the test group was small, but have inspired some interesting theses.

  1. It is theoretically possible to obtain a vegan vitamin B12 supply
  2. This is achieved through specific endogenous microorganisms 
  3. It requires a high level of physical health, in particular a healthy intestinal flora
  4. It is dependent on the presence of the right microorganisms (probiotics)
  5. A low stress level is favorable (=low B12 needs), high consumption of raw foods (=basic nutrition) and minimal exposure to pollution

The B12 Cobalt Compound

Vitamin B12 producing microorganisms are heavily dependent on a supply of trace element cobalt; the central atom of vitamin B12 (hence the name cobalamin).

Agricultural observations show interesting developments: cows with a normal diet and that consume grass can no longer survive without cobalt or B12 supplements. Due to decreasing cobalt content in fodder and grass, calves can die as a result of vitamin B12 deficiency. The deficiency leads to rapid weight loss, anemia and ultimately death. Therefore, cows almost always rely on a supplement for either cobalt or B12 in the modern day.

Even some plants die without additional cobalt provisions nowadays. Soy beans are especially vulnerable to low cobalt levels in the humus and so are often fertilized with cobalt.

This opens up an interesting thought: if the body’s vitamin B12 producing qualities were being affected in the same way that animals in the industrial word our, perhaps we would care more about the protection of trace elements?

Exact figures are not available for cobalt, however, studies looking into other similar minerals show that trace element levels are continuously decreasing.6 Dan Reeter a researcher at the Bio-Systems Labs in Colorado, USA is certain that cobalt soil content has dropped significantly: 

“I can say with certainty there’s a decline of soil cobalt. Confirm this for yourself. Simply to pick any Ag magazine—they all push cobalt supplements, spurred by B12-poor condition of crops.”7

Vitamin B12, the Vegan Diet and Industrialization

This all points towards an interesting conclusion: although vegan diet cannot sufficiently cover the bodily needs for vitamin B12 this is less so to do with the vegan diet per se, and more points towards the implications of a number of environmental changes resulting from industrialisation and the unnatural lifestyles of industrialised nations.

Industrial agriculture leaches the soil and destroys the microbial flora, lowering the nutritional value of foods grown in it. Typical lifestyles involving unhealthy diets, high stress and often irritated intestinal flora means that the body is in need of even higher levels of vitamin B12.

It is interesting how the condition of the soil appears to reflect the condition of the intestinal flora: in both circumstances the natural harmony of bacterial flora is strongly influenced by unnatural lifestyles. 

Meeting B12 Needs as a Vegan

The bottom line is unfortunately that vegans are mostly advised to take supplements as an additional B12 supply. The reasons for this are not that this dietary method is insufficient, however, but rather that it requires a high level of naturalness, which is very difficult to achieve in the modern day. 

A healthy lifestyle, a systematic structure of the intestinal flora, coupled with a nutrient-rich, basic diet and a good level of general health would certainly seem to be a prerequisite for a vegan B12 supply without supplements.

Unfortunately, these needs are mostly unfulfilled in modern society, but luckily there are plenty of suitable vegan vitamin B12 supplements, designed to help meet the body’s requirement. With this small addition, a vegan diet can be considered amongst the healthiest diets possible. 

How Much Vitamin B12 is Needed in the Vegan Diet

The assumption that a specific B12 need will be met through a natural vegan diet is incredibly unrealistic. This is because there are several different factors which affect the body’s requirement and absorption of vitamin B12. Above all else, the following two factors play a large role:

  • Overall general health (particularly of the stomach and intestine)
  • Stress levels

From this, the following rough guides for levels of vitamin B12 required by the body can be ascertained:

  1. Optimal health, as described above —> 5 – 10 µg per day
  2. Good health, generally good lifestyle —> 250 µg per day
  3. High stress levels, serious physical sport or a very unhealthy lifestyle (smokers, drug users etc) —> 500 µg per day

As with all cases, the purest possible B12 supplements without additives are recommended, as additives can sometimes impair the absorption rate of B12. 

The best active ingredients available are methylcobalamin or a combination of methylcobalamin and hydroxocobalamin. The latter is seen as particularly advantageous because of its additional detoxifying effect and good sustained release function. 


1 M. J. Albert, V. I. Mathan & S. J. Baker. Vitamin B12 synthesis by human small intestinal bacteria. Nature 283, 781-782 (21 February 1980). doi:10.1038/283781a0
2 Contribution Of The Microflora Of The Small Intestine To The Vitamin B12 Nutriture Of Man. Nutrition Reviews, 38: 274–275. doi: 10.1111/j.1753-4887.1980.tb05958.x
3 Herrmann W, Schorr H, Obeid R, Geisel J. Vitamin B-12 status, particularly holotranscobalamin II and methylmalonic acid concentrations, and hyperhomocysteinemia in vegetarians. Am J Clin Nutr 2003;78:131–6
4 Ibrahim Elmadfa and Ingrid Singer: Vitamin B-12 and homocysteine status among vegetarians: a global perspective. Am J Clin Nutr 2009 89: 1693S-1698S
5 LAWRENCE J. BRANDT, LESLIE H. BERNSTEIN, WAGLE ABDUL; Production of Vitamin B12 Analogues in Patients with Small-Bowel Bacterial Overgrowth. Annals of Internal Medicine. 1977 Nov;87(5):546-551.
6 Thomas D. A study on the mineral depletion of the foods available to us as a nation over the period 1940 to 1991. Nutr Health. 2003;17(2):85-115. Review. PubMed PMID: 14653505.

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