The issue of B-12 deficiency is of great concern for myself and others in the community. After switching to a vegan diet, I looked for alternative sources of cobalamin. Currently, I buy nutritional yeast in bulk from various stores, sometimes take a supplement, and eat other fortified foods. A claim I read online states that rejuvelac contains B-12. Rejuvelac is a fermented drink, popularized by Ann Wigmore. It is created by soaking wheat berries in water and straining the liquid once it becomes milky. I have used it in vegan cheese recipes, specifically one created by Miyoko Schinner in The Homemade Vegan Pantry.

I have found little supporting evidence while searching for an answer as to whether rejuvelac contains sufficient levels of B-12 for a vegan or vegetarian.

From additional research, cobalamin levels in foods are related to the level of cobalt in the soil that the crop of interest grew and how reactive bacteria were; B12 is only created by bacteria as a by-product of a reaction. According to this source, cobalamin created by fermentation is called pseudo-cobalamin and "competes with other forms of B-12".

How is B-12 created industrially? Can psuedo-cobalamin be converted into other forms? What is a reliable source for cobalamin rich plants?

  • I hope by "cobalamin" you mean methylcobalamin Oct 24, 2020 at 1:13
  • I'm not sure, actually. What is the difference and why is it important?
    – defarm
    Oct 26, 2020 at 21:42

2 Answers 2


Currently, there seem to be no natural plant food that would contain vitamin B12 in the amounts sufficient for humans.

Some plant foods contain vitamin B12, but this is either inactive - pseudovitamin B12 - (in spirulina, chlorella, tempeh, miso, kombu) or not present in sufficient amounts (in white button mushrooms, Korean purple laver or nori or nutritional yeast); human intestinal bacteria may also produce some vitamin B12 but not in sufficient amounts (Vegan Health, Vegetarian Nutrition Dietetic Practice Group).

There seems to be no reliable information about the amount and activity of vitamin B12 from rejuvelac on any serious health website, so I would not use it as a source of vitamin B12. I'm also not aware of any natural process that would convert inactive forms of vitamin B12 into the active ones.

Yes, vitamin B12 supplements can be produced from microorganisms (The Vegan Society).

The only reliable vegan sources of B12 are foods fortified with B12 (including some plant milks, some soy products and some breakfast cereals) and B12 supplements. Vitamin B12, whether in supplements, fortified foods, or animal products, comes from micro-organisms.


B12 is found in animal products, with meat containing the greatest amounts.

Vegetarians can get B12 from milk and yogurt as well as cheese and eggs, in smaller amounts.

Vegans have to get B12 through supplementation or fortification. Nutritional yeast is commonly recommended. Some cereals and plant-based milks are also fortified.

I've recently heard a vegan group making the recommendation to avoid washing your produce because dirt found on your fruit and vegetables contains B12. I hate that it needs to be said, but please don't do this. It's not sanitary, and you will eventually get sick!

Vegan-friendly B12 comes from micro-organisms


  • 4
    Most of your answers seem to link to your own web site. That's fine, within reason, but you need to be explicit about it. See How not to be a spammer.
    – tripleee
    Apr 8, 2020 at 3:14
  • 3
    I think this answer doesn't really tie in well with what the question was. Unless necessary try to avoid giving general answers to specific questions. This one did not ask what B12 is or where to get it but very specifically if it is found in rejuvelac. I'd also suggest to use links to your website only when relevant and always try to at least quote fitting parts from them so that when/if the links break the answer still makes sense. Apr 8, 2020 at 6:14

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