Is B12 methylcobalamin vegan

Vitamin B12: supply with a vegan diet

While most vitamins and minerals are particularly abundant in a vegan diet, one vitamin deserves special attention: The vitamin B12 formed by microorganisms is rarely found in plant-based foods. That is why it is important that vegans consciously make sure they are getting enough food.

A well-planned vegan diet is healthy

A well-planned vegan diet is healthy, provides Benefits in the prevention and treatment of certain diseases and is suitable for people in every phase of life, writes the Academy of Nutrition and Dietetics, the largest specialist society for nutrition, in its position paper on vegetarian diets. Well planned means being diverse on the basis of a lot fresh vegetables and fruits, whole grains, legumes, nuts and oilseeds as well as high-quality oils to nourish. This not only provides you with sufficient protein and many essential vitamins and minerals, but also takes in numerous health-promoting dietary fibers and secondary plant substances. For the Academy of Nutrition and Dietetics, well-planned also means targeting an adequate supply of Vitamin B12 to pay attention and to take food supplements (so-called "supplements") or fortified foods. The essential nutrient is not found in relevant quantities in plant-based foods.

What is Vitamin B12?

Vitamin B12 is a complex molecule belonging to the group of Cobalamins is counted. These contain a corring skeleton and cobalt as a central atom. Different molecular residues, so-called ligands, are in turn bound to the cobalt atom. Depending on the ligand, different types of cobalalin arise, for example Cyanocobalamin, methylcobalamin, hydroxocobalamin or Adenosyl cobalamin. While cyanocobalamin is a synthetic form, the other types of cobalamin mentioned occur naturally. Methyl- and adenosylcobalamin are effective as coenzymes in the human body. However, the other forms of cobalamin can be converted to the two active forms in the body. Further changes to the corring framework are also possible, such as additional side chains elsewhere or missing components. In this case, it is not an effective vitamin B12, but rather inactive analogues.

Functions in the body

As a cofactor of enzymes, vitamin B12 is involved in various biochemical reactions in the body. It helps break down the amino acid homocysteine ​​and converts methylmalonic acid and leucine. To put it simply, the vitamin is important for that DNA synthesis and the Cell division, for the Red blood cell formation and the Keeping the nervous system healthy.

Symptoms of a Deficiency

An undersupply can thus lead to a form of anemia, the so-called megaloblastic anemia, to lead. The red blood cells are abnormally enlarged and symptoms such as pale skin, mucosal disorders, weakness, difficulty concentrating and tiredness occur.

However, these are more serious than the symptoms of impaired blood formation Damage to the central nervous system. In addition to sensory disorders such as "ants tingling" in the hands and feet, there can be reflex and movement weaknesses, disorders of movement coordination and psychiatric disorders such as confusion, hallucinations, memory disorders and even psychoses. Symptoms of paralysis can also arise. These symptoms are in part irreversible, can therefore not be reversed even with a high dose of vitamins, once they are present.

The two groups of symptoms can occur independently of one another. The neurological symptoms in adults often only appear after several years - sometimes it takes 20 years or even longer. The problem here, however, is that the symptoms of anemia can be masked by a high intake of folic acid, which is found a lot in plant-based foods. At the same time, however, the irreversible neurological changes progress so that permanent damage to the central nervous system can occur without warning. Take special care in infants and young children commanded. You are very sensitive to a vitamin B12 deficiency, and you can Developmental disorders and nerve damage arise.

In addition, a vitamin B12 deficiency increases the Homocysteine ​​levelswhich in turn is the emergence of Cardiovascular diseases can favor.

Vitamin B12 deficiency in an omnivorous diet

A deficiency in vitamin B12 is often associated with a vegan diet. In fact, a deficiency also occurs frequently in meat eaters, especially in old age. According to the ÖSES study, around 20% of all elderly people in Austria have too low a vitamin B12 level. This can cause memory loss more quickly and possibly a higher risk of dementia. The reason for this is often one Gastritits (Inflammation of the gastric mucosa), which leads to the fact that the "intrinsic factor" necessary for active absorption can no longer be formed.

Absorption in the body

The human body has various options for absorbing the vitamin from food. The most important form is the one already mentioned active absorption: Most of the time, B12 is bound to proteins in food. It is separated from these in the stomach by special enzymes, then bound to a transport protein called haptocorrin and transported to the small intestine. The is also formed in the stomach Intrinsic factor, another transport molecule. This combines with B12 in the small intestine and transports it to the special receptors in the intestinal mucosa, through which the vitamin reaches the mucous membrane cells. About this active absorption you can a maximum of 1.5 µg per meal or vitamin dose as the number of receptors is limited.

A second form of recording is the passive diffusion dar: Diffuses independently of the intrinsic factor approx. 1% the absorbed B12 dose in the mucous membrane cells. However, since the percentage is very low, relevant amounts can only be absorbed via passive diffusion at high doses. In addition, unbound vitamin B12 can also be found on the Oral mucosa be included.

Feeding recommendations

The Estimated value for adequate intake according to the German Nutrition Society (DGE) for adults is 4 µg per day. This value is based on the assumption that small amounts of vitamin B12 are ingested through food several times a day. Due to the limited active absorption of 1.5 µg per meal, the body must with one-time supplementation per day fall back on passive diffusion. Since only 1% is absorbed here, the dose administered should be significantly higher, namely at least 10 - 20 µg be. If, however, the supplementation only takes place once a week, it should at least 2000 µg be.
According to the European Food Safety Authority (EFSA), there is no evidence of negative health effects even at very high doses of 1000 to 5000 µg.

Vitamin B12 in plant foods

Vitamin B12 is always produced by microorganisms. B12-producing bacteria are found in the intestines of certain animals, but also in the soil and in contaminated water. In food the vitamin is only in Animal products such as meat, milk and eggs in relevant quantities. Plant-based foods, which have been reported and are still being reported to be sources of vitamin B12, mostly contain mostly or exclusively the inactive ones mentioned above Vitamin B12 Analogs. The reason for the misjudgments was and is the application of inaccurate measurement methods, which are still often used today.

Larger amounts of B12 were only found in some studies of the algae nori and chlorella. However, the fluctuations in the content were very large and in some cases large amounts of analogues were also present. Previous tests on humans indicate that even when consumed in high quantities, nori does not provide enough B12 to meet human needs. In the case of the blue-green algae Spirulina it is also largely analogues.

Very small amounts of vitamin B12 could also be detected in fermented products such as sauerkraut or tempeh. However, these quantities are not enough to meet demand. It is unclear whether and to what extent B12 passes through symbiotic bacteria, bacterial contamination or contamination with excrement, as well as insects gets into certain plant-based foods. Due to the usually very small and, above all, unpredictable quantities, the mentioned plant-based foods represent not a serious source of vitamin B12 represent.

Supply with vegan diet

Studies with vegan peoplefrom the USA show in some cases very different results in terms of vitamin B12 supply compared to Austria and Germany (see Fig. 1):

While the Vitamin B12 levels in German-speaking countries are significantly lower among vegans than among lacto-ovo vegetarians and, above all, omnivores, in the present US study, they are almost as high in vegans as in omnivorous people. The opposite result is shown for the homocysteine ​​level (see Fig. 2): In the Austrian and German studies, vegans have the highest values, in the US study they are even slightly lower for vegans than for omnivores. It should be noted here that an increased homocysteine ​​is a risk factor for cardiovascular diseases and vegans in the Heidelberg Vegetarian Study, the only long-term study carried out in Germany with vegan people, with regard to their risk of death, especially with regard to cardiovascular diseases , fared significantly worse than vegans from American long-term studies.

What are the reasons for these different results?

In the US, numerous are using the vitamin fortified products Available in normal supermarkets: The range extends from breakfast cereals, plant-based drinks and yeast flakes to vegan meat alternatives. As a result, many American vegans automatically take in B12 without specifically worrying about it. In Austria and Germany, however, there are only a few productsto which a relevant amount of B12 has been added. For example, you would have to drink almost a liter of the frequently fortified soy milk a day to get enough of the vitamin. In principle, this should not be seen as a disadvantage, but it does mean that individual responsibility The question is: Those who follow a vegan diet either have to be conscious supplement or at least check the B12 levels regularly to let.

Is a supplement unnatural?

Vegan diets are sometimes criticized for not being “natural” when supplementation is required. What is forgotten here is that Feed enriched with vitamin B12 and the supply of omnivores is mostly done through supplementation - an indirect one, which is anything but natural due to the living conditions of the animals. According to estimates by the Austrian Agency for Health and Food Safety (AGES), in Austria for the animal nutrition sector 57–60 tons of vitamin B12 supplements per year used.

Vegan alternatives

In order to ensure a sufficient supply of nutrients, they are primarily suitable for vegans Food supplements. There are several vegan products on the market that vary widely in dosage. Supplements with 1 µg are just as available as those with 1000 µg or even significantly more. While 1 µg is actively absorbed and passive diffusion does not play a role, absorption at 1000 µg occurs almost exclusively via passive diffusion (here 1.5 µg is actively absorbed, but 1%, i.e. 10 µg, diffuses passively). The Ingestion frequency must therefore be adapted to the dosage become.

Dosage recommendations

  • 1 µg: 2–3 times a day
  • 10 µg: 1-2 times a day
  • 100 µg: 1 time a day
  • 250 µg: 5–7 times a week
  • 500 µg: 3–4 times a week
  • 1000 µg: 2 times a week

Recommended dietary supplements are, for example:

  • Solgar 1000 µg vitamin B12:Order pharmacy zur Kaiserkrone or online
  • Jarrow Methyl B12 1000 µg: vegan online mail order business
  • Vantastic Foods Vitamin B12 250 µg: vegan online mail order business
  • Higher Nature Sublingual Powder: Order pharmacy zur Kaiserkrone or online
  • VEG shop, vegan shops and online mail order business
  • BjökoVit: various products, online shipping
  • Innonature Vitamin B12 drops:Online delivery

(Attention: some food supplements can also be based on analogues. The supplements listed here, however, contain easily usable vitamin B12.)

Further options for the B12 supply

The vegan Vitamin B12 toothpaste from Santé is a good alternative to getting enough supplies. Here, the nutrient is absorbed through the oral mucosa and is well absorbed by the body. No intrinsic factor needs to be formed for this variant, which is why it is also suitable for people with absorption disorders. According to an effectiveness study carried out by the Institute for Alternative and Sustainable Nutrition (IFANE), the exclusive use of toothpaste can lead to a significant improvement in the vitamin B12 status. It's available in health food stores, health food stores, and vegan stores.

It can also be administered intramuscularly (into the muscle) or subcutaneously (under the skin) Syringes to fall back on. These are particularly preferred when the body's stores are to be replenished quickly, but can also serve as the sole source of B12 in the long term.

Methyl or cyanocobalamin?

Cyanocobalamin has one high chemical stability and has therefore already for a long time in prevention and treatment a vitamin B12 deficiency. On the other hand, many websites argue that methylcobalamin should be preferred, as cyanocobalmin must first be converted by the body and it contains cyanide.

If you take a closer look at the metabolic processes in the body, it quickly becomes apparent that Methylcobalamin has no conversion benefit brings: With every type of vitamin B12 supplied, the Ligand (e.g. the methyl or cyanide residue) initially split off after entering the cell. Only in a further step is a methyl or adenosyl group attached to form the coenzymes.

Also in relation to that contained Cyanide can be warned: Although this is actually a toxic substance, the dose is so low that for a 50 kg person with a high intake of 1000 µg per day it is only 0.8 percent of the ADI value (Acceptable Daily Intake) - this indicates the amount that can be ingested daily for a lifetime without any health risk.

Only in a few exceptional cases Another type of cobalamin than cyanocobalamin, such as methylcobalamin, should be preferred: For reasons of safety, cyanocobalmin should not be used in rare diseases with a disorder of the cyanide metabolism such as chronic kidney disease and Leber’s optic atrophy.

Determination of vitamin B12 supply

A regular status check in the form of a blood test at least every 2–3 years is recommended. The Standard vitamin B12 value in the serum is not sufficient for this, as it is a late, relatively insensitive and unspecific parameter. The majority of the measured vitamin B12 is bound to the transport protein haptocorrin and is therefore not effective. Various other values ​​can be used for diagnostics, which provide reliable information, especially in combination: The active form Holo-Transcobalamin II (holoTC) As the earliest biomarker in the event of a decrease, it can be the first to indicate a vitamin B12 deficit and is therefore preferable. The functional marker Methylmalonic acid (MMA) increases when the B12 stores are empty. Also increased Homocysteine Together with a low vitamin B12 level, this can indicate a B12 deficiency. However, this can also increase due to a lack of folic acid and vitamin B6, as well as alcohol, nicotine and stress.

According to Herrmann and Obeid, the following values ​​indicate a defect:

  • holo-TC: <35 pmol / l
  • MMA: > 271 nmol / l
  • Homocysteine: > 12 µmol / l

Is it possible to overdose on vitamin B12?

For a long time, a high vitamin B12 intake was considered harmless to health. Until a few years ago it was assumed that in rare cases acne could be the only potential side effect of a very high dose. For some years now, however, there has been increasing evidence that an overdose of vitamin B12 could increase the risk of certain types of cancer. The evaluation of the VITAL cohort in 2017 showed one for men increased risk of lung cancer with permanent supplementation of more than 55 µg per day. In these cases, the risk of lung cancer was doubled compared to non-users. In these cases, the risk of smokers was three to four times as high. The causal relationship between a very high vitamin B12 supplementation and the risk of lung cancer was confirmed in 2019 by a study by Fanidi et al .: A doubling of the vitamin B12 concentration in the blood increased the risk of developing lung cancer by 15% compared to the Comparison group (with usual vitamin B12 concentrations in the blood).

What does this mean in practice?

A safe upper dose limit cannot be derived from these studies. Further studies are urgently needed for this. But it turns out that one high levels of vitamin B12 in the blood is decisive for the increase in risk. Based on the results of the studies to date, it can be assumed that a high level of vitamin B12 supplementation is only problematic if the concentration in the blood is also increased. Regular tests are therefore strongly recommended. As long as the vitamin B12 concentration in the blood is not increased, a supplement of 1000 µg twice a week is considered - according to the current state of knowledge - not to increase risk.


  • Vitamin B12 is not contained in relevant quantities in plant-based foods.
  • A reliable and ideal supply of vitamin B12 with a vegan diet can easily be ensured by using dietary supplements and / or fortified foods and / or fortified toothpaste and / or syringes.
  • A blood test every 2-3 years provides additional security. holo-TC is the first choice when examining vitamin B12.

Webinar to look up

We have developed a free webinar on the subject of "Vitamin B12: Supply with a vegan diet". It can be looked up here.

Sources and further reading

  • Chang-Claude J, Hermann S, Eilber U, Steindorf K (2005): Lifestyle determinants and mortality in German vegetarians and health-conscious persons: results of a 21-year follow-up. Cancer Epidemiol Biomarkers Prev 14 (4): 963-8.
  • Craig WJ, Mangels AR (2009): Position of the American Dietetic Association: Vegetarian Diets. Journal of the American Dietetic Association, 109: 1266-1282.
  • Davey GK, Spencer EA, Appleby PN, Allen NE et al. (2003): EPIC-Oxford: lifestyle characteristics and nutrient intakes in a cohort of 33 883 meat-eaters and 31 546 non meat-eaters in the UK. Public Health Nutr 6 (3): 259-69.
  • DGE (German Society for Nutrition), ÖGE (Austrian Society for Nutrition), SGE (Swiss Society for Nutrition Research), SVE (Swiss Nutrition Association) (ed.) (2008): Reference values ​​for nutrient intake. Neuer Umschau Buchverlag, Neustadt a. d. Weinstrasse, 3rd corr. Reprint, p. 131
  • Elmadfa I et al. (2008). Austrian Nutrition Report 2008. 1st edition.
  • Elmadfa I, Leitzmann C (2004). Human nutrition. Ulmer, Stuttgart, 4th edition.
  • Haddad EH, Berk LS, Kettering JD, Hubbard RW, Peters WR (1999). Dietary intake and biochemical, hematologic, and immune status of vegans compared with nonvegetarians. Am J Clin Nutr, 70: 586-93.
  • Herrmann W, Obeid R, Schorr H, Geisel J (2005). The usefulness of holotranscobalamin in predicting vitamin B12 status in different clinical settings. Curr Drug Metab, 6: 47-53.
  • Key TJ, Fraser GE, Thorogood M, Appleby PN, Beral V, Reeves G, Burr ML, Chang-Claude J, Frentzel-Beyme R, Kuzma JW, Mann J, McPherson K (1999). Mortality in vegetarians and nonvegetarians: detailed findings from a collaborative analysis of 5 prospective studies. Am J Clin Nutr, 70 (3 Suppl.): 516-542.
  • Mądry E, Lisowska A, Grebowiec P, Walkowiak J (2012). The impact of vegan diet on B-12 status in healthy omnivores: five-year prospective study. Acta Sci Pol Technol Aliment, 11: 209-12.
  • Leitzmann C, Keller M (2013). Vegetarian diet. Stuttgart, Eugen Ulmer Verlag (3rd updated edition).
  • Majchrzak D, Singer I, Männer M, Rust P et al. (2006). B-vitamin status and concentrations of homocysteine ​​in Austrian omnivores, vegetarians and vegans. Ann Nutr Metab, 50 (6): 485-91.
  • Norris M., Messina V (2011). Vegan for Life: Everything You Need to Know to Be Healthy and Fit on a Plant-Based Diet. Cambrige, Da Capo Pr.
  • Pawlak R, Parrott SJ, Raj S, Cullum-Dugan D, Lucus D (2013). How prevalent is vitamin B (12) deficiency among vegetarians? Nutr Rev, 71: 110-7.
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