Vitamin B12

No E-numberVitamins & mineralsOrigin: Lab-made

Get a personal answer

Pick your family’s diets in the bar above.

Every diet

VeganYes

It is made by bacteria or synthesised, so plant milks can carry it.

Gluten-freeYes

HalalYes

KosherYes

KetoYes

No carbohydrate.

Low-FODMAPYes

The short answer

Vitamin B12 is the vitamin only bacteria make, so it reaches plant-based food through fortification or a bacterial source. It is safe even in large doses, has no upper limit, and is worth checking if you eat no animal products.

94/100

Generally safe

Fine for most people at normal amounts.

E-numberNone

Comes fromLab-made

What it doesVitamins & minerals

Glycemic index—

Daily limitNot set

Also calledVitamin B12, Cyanocobalamin

Rules by country

🇺🇸 US FDAApproved

🇪🇺 European UnionApproved

🇨🇦 Health CanadaApproved

CaliforniaNo extra rules

In the United States, vitamin B12 is permitted as a nutrient additive under the FDA's food additive rules for special dietary and nutritional additives, and it is used in supplements and fortified plant milks. It has no E-number: the EU authorizes it as a nutrient for fortification under Regulation (EC) No 1333/2008 rather than as an additive, and EFSA set no upper level for it.

Daily limit: Experts haven’t set a number because normal food amounts are far below any level of concern.

What is it?

Cyanocobalamin is the manufactured form of vitamin B12, and the body treats it the same as the B12 that arrives in meat, fish or dairy. It has one job no other nutrient does: it carries a cobalt atom, and that is what lets it build red blood cells and keep the sheath around your nerves in good repair. Fortified versions are stable enough to sit on a shelf for a year, and one tablet can carry a thousand micrograms, hundreds of times the daily requirement.

Where it comes from: Cyanocobalamin is made by bacteria and purified for use in food, though most vitamin B12 is produced by industrial fermentation. It is the one vitamin no plant makes on its own, so it reaches plant-based food only through bacterial activity or fortification.

Why it’s in food

Fortifying plant milks and spreads
Enriching breakfast cereals
Covering the gap on a vegan diet
Adding to supplement tablets
Treating a confirmed deficiency

Often found in

Fortified plant milksBreakfast cerealsNutritional yeastMultivitamin tabletsEnergy drinksFortified plant-based yogurts

Also listed as: Vitamin B12, Cyanocobalamin, Cobalamin, Vitamin B12 (cyanocobalamin)

Health & gut impact

No upper levelBenefit

EFSA reviewed vitamin B12 and could not set an upper level for it, because the body stores only a few micrograms and the rest passes out in the urine. Nothing in the review pointed to a harmful dose, so a fortified food or a supplement is not where the risk sits.

EFSA Journal, scientific opinion on vitamin B12

Vegan diets and deficiencyUnder study

EFSA puts the daily requirement at 2.5 micrograms, and the only natural sources are animal products and bacteria. On a fully vegan diet that gap is easy to miss, which is why fortified milks and yeast extracts carry it and why the label on a plant milk is worth reading.

EFSA, dietary reference values for vitamin B12

When absorption failsUnder study

Stomach acid is what releases B12 from food, so long-term metformin users and people on acid-blocking medicines can run low even while eating meat and dairy. Anyone with a diagnosed deficiency needs high-dose tablets or injections, and those have to come from a doctor.

NHS, vitamin B12

What can I use instead?

Nutritional yeast

Ratio: Use a fortified pouch and read the micrograms on the label

Best for: Adding B12 to a vegan diet without a tablet

Fortified oat milk

Ratio: One 250 ml serving, with around 1 microgram in most brands

Best for: The everyday vegan source

Meat, fish and eggs

Ratio: One serving a few times a week

Best for: Diets that are not vegan

More vitamins & minerals:

CholineCholine is a nutrient most people get enough of from eggs, meat and soy, so it is rarely something to hunt down. It is added on purpose to infant formula, where the amount is regulated, and EFSA sets 400 mg a day for adults.Use in moderation Ferrous sulfateFerrous sulfate is the iron added to flour, bread and cereals, and it is safe at fortification amounts. The catch is the dose: a large single serving upsets the stomach, so read the milligram amount on the label, not the product count.Use in moderation Folic acid (Vitamin B9)Folic acid is the synthetic form of vitamin B9, and it is added to flour, bread and breakfast cereals on purpose. It is safe at fortification levels, but EFSA caps it at 0.6 mg a day for adults because a large intake can hide a vitamin B12 deficiency.Use in moderation Niacin (Vitamin B3)Niacin is vitamin B3 in the nicotinic acid form, added to flour and cereals because many diets fall short of it. Fortification amounts are small and safe, but a 100 mg supplement is a bigger dose, and that much nicotinic acid makes many people flush.Use in moderation

Common questions

Do vegan foods have vitamin B12?

Not unless they are fortified, because the only natural sources are animal products and bacteria. A vegan needs a fortified milk, a fortified yeast extract or a supplement to cover the 2.5 micrograms a day the body needs.

Is too much vitamin B12 dangerous?

No. EFSA could not set an upper level for vitamin B12, because the body does not accumulate it and the rest passes out in the urine. The side effect people report from high doses is a temporary pink flush in the face.

How do I know if I am deficient?

Tiredness, breathlessness and pale skin are the usual signs, but a blood test for B12 and folate is the only reliable answer. Tingling in the hands and feet can appear too, and those are the symptoms that do not reverse without treatment.

Is Vitamin B12 safe?

Generally safe (94/100). In the United States, vitamin B12 is permitted as a nutrient additive under the FDA's food additive rules for special dietary and nutritional additives, and it is used in supplements and fortified plant milks. It has no E-number: the EU authorizes it as a nutrient for fortification under Regulation (EC) No 1333/2008 rather than as an additive, and EFSA set no upper level for it.

Is Vitamin B12 vegan?

Yes. It is made by bacteria or synthesised, so plant milks can carry it.

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Scientific sources & regulatory citations

EFSA Journal, scientific opinion on vitamin B12
EFSA, dietary reference values for vitamin B12
NHS, vitamin B12

CAS 68-19-9