BLOG Knowledgebase

Achilles’ Heel Vitamin B12 – Who needs it, who has it?

Where can we find vitamin B12?

Vitamin B12 (cobalamin) is a water-soluble vitamin that cannot be made by animals nor by humans nor plants but by bacteria and archaea. These bacteria grow e.g. by guts in all animals. Cobalamin is involved in our nervous system, the formation of blood cells, the metabolism of all cells, DNA synthesis, and fatty acid, and amino acid synthesis.
In the past, we got enough vitamin B12 while eating excrement, dirty plants, and drinking fresh water out of natural water sources. But more and more countries chlorinate their water to kill any bacteria due to rising environmental pollution. The positive thing in our sterilized world is that we do not get cholera any longer but neither we get enough cobalamin.

But why can we get B12 by eating animal products if they cannot produce it by themselves?

Meat, fish, dairy, and other animal products contain B12 just because they got fed with it! So, why shouldn’t we eat B12 directly instead of feeding it to animals and then eating the animals? There are some traces of cobalamin in some algae (e.g. spirulina), organic and unwashed leguminous plants, and mushrooms but not enough to have a safe source.

Animal products are not good B12 sources at all. A study shows that just approximately 4 % of the cobalamin amount of scrambled eggs is absorbed. You need to eat about 300 eggs a day to get your daily intake recommendation. Not to mention the devastating amount of cholesterol and fats you would consume!

B12-Supplementation is the only one we really need to take care of
B12-Supplementation is the only one we really need to take care of

Why do we need vitamin B12?

Although recommendations for cobalamin are very small: The recommended daily intake is about 2.5-7 µg/day for adults. Vitamin B12 deficiency is a serious problem leading ultimately to anemia, chronic fatigue, neuropsychiatric disorders, irreversible nerve damage, and relative hyperhomocysteinemia. Plus, brain shrinkage, cognitive deficits, fatigue, headaches, breathlessness, strokes, bone damage, depression, and even DNA damage can be caused by B12 deficiency.

Not only vegans but also vegetarians and all omnivores should take cobalamin supplements. You cannot take too much of it! You don’t have to get this vitamin each day due to our body’s ability to store B12  in the liver worth for 3-5 years. If your body has enough of it you simply pee the excess out – same for vitamin D. Still, you shouldn’t take the recommended amount for a whole year in a few days. Since our skin is one of our main detoxifying organs, it may cause a rash.

While moderate overconsumption causes no serious harmful effects, deficiencies have serious harmful effects, especially for pregnant women and children.
Several studies show that the safest, cheapest, and most efficacious way to get B12 is oral supplementation whether with tablets, toothpaste, or enriched food. Furthermore, you can also get injections but there’s no need for doing so. The cobalamin recommendation goes for everyone – not just for those following a vegan or plant-based diet.

The only supplement we definitely need to take

B12-tablets are the only supplements we really need to take. I take these tablets* (avoid tablets packed in plastic!) from time to time and use an enriched toothpaste. If you want to check your cobalamin-blood levels, you should mention it at a blood withdrawal. Usually, it is not tested.

There is only one thing you should really take care of: Supplements must contain “methylcobalamin” – the best source for B12 for our body.

Did you ever take care of having enough vitamins? Do you take supplements? I’m curious about your answers!
Do you like this blogpost? Feel free to share it and stay tuned on my Facebook-Fanpage as well. 🙂

Check the studies used for this blog post

Bor, M. V./von Castel-Roberts, K. M./Kauwell, G. P. A./Stabler, S. P./Allen, R. H./Maneval, D. R./Bailey, L. B./Nexo, E. 2010: Daily intake of 4 to 7 µg dietary vitamin B-12 is associated with steady concentrations of vitamin B-12–related biomarkers in a healthy young population, in: American Journal of Clinical Nutrition, 2010, Vol. 91, pp. 571-577.

Donaldson, M. S. 2000: Metabolic Vitamin B12 Status on a Mostly Raw Vegan Diet with Follow-Up Using Tablets, Nutritional Yeast, or Probiotic Supplements, in: Annals of Nutrition and Metabolism, Vol. 44, 2000, No. 5-6, pp. 229-234.

Graham, I. D./Jette, N./Tetroe, J./Robinson, N./Milne, S./Mitchell, S. L.. 2007: Oral cobalamin remains medicine’s best kept secret, in: Archives of Gerontology and Geriatrics, Vol. 44, 2007, pp. 49-59.

Levine, A. S./Doscherholmen, A. 1983: Vitamin B12 bioavailability from egg yolk and egg white: relationship to binding proteins, in: American Journal of Clinical Nutrition, Vol. 38, 1983, No. 3, pp. 436-439.

Madry, E./Lisowska, A./Grebowiec, P./Walkowiak, J. 2012: The impact of vegan diet on B-12 status in healthy omnivores: five-year prospective study, in: Acta Sci. Pol., Technol. Aliment., Vol. 11, 2012, No. 2, pp. 209-213.

Scott, J. M. 1997: Bioavailability of vitamin B12, in: European Journal of Clinical Nutrition, Vol. 51, 1997, No. 1, pp. 549-553.

Su, T.-C./Torng, P.-L./Jeng, J.-S./Chen, M.-F./Liau, C.-S. 2011: Arterial function of carotid and brachial arteries in postmenopausal vegetarians, in: Vascular Health and Risk Management, 2011, No. 7, pp. 517-523.

Watanabe, F. 2007: Vitamin B12 Sources and Bioavailability, in: Experimental Biology and Medicine, Vol. 232, 2007, No. 10, pp. 1266-1274.

*This is an affiliate link. If you buy something using this link, I get a small commission without you having to pay more. But I don’t promote anything I don’t believe in wholeheartedly.
I’m not a fan of Amazon but you can use it as a search engine and order at the seller directly!

You Might Also Like


  • Reply
    Torne Velk
    10. March 2019 at 6:16

    I take b12 now thanks to you x

    • Reply
      10. March 2019 at 20:23

      Hi Torne, my dear!
      Glad you came over and send you kisses from Munich :*

  • Reply
    14. May 2017 at 11:35

    Excellent article, I had no idea animals were fed B12! Another point to make in promoting veganism.

    • Reply
      14. May 2017 at 18:01

      Thank you, Justine! Indeed, no need for meat 🙂
      All the best for you,

Leave a Reply