How Long Can Vegans Go Without Vitamin B12?


Vitamin B12 is the only “mandatory” supplement that vegans need to take, although you can technically get enough from fortified foods if you really pay attention.

Because of where humans get B12 naturally, vegans don’t tend to get much (if any) from whole food sources.

People in general get most of their B12 from animal products.

The good news is that your body can store a lot of it.

How Much Vitamin B12 Can the Body Store?

deva b12 supplement

Depending on your size, you can store between 2,000 and 4,000 micrograms (mcg) in your body, mainly in the liver.

Yes, that’s only a fraction of a gram, which doesn’t sound like a lot, but the recommended daily allowance (RDA) of vitamin B12 is just 2.4 mcg.

In theory, if your vitamin B12 stores were full before going vegan, you could be fine for something like 3-5 years.

The problem is that you don’t know how full your stores are. If you want to be sure, get a blood test.

In addition, having too much vitamin B12 isn’t a bad thing, but not having enough can cause serious health issues.

So while you don’t need to start supplementing right away, it’s not a bad idea to pick one up at some point. Here’s a list of the best vegan vitamin B12 supplements (some supplements are not vegan).


Your body’s stores of vitamin B12 can last for years, so most vegans don’t need to panic about getting a supplement right away.

Can I Survive Without a B12 Supplement?

While supplements are one option, another option is to get B12 from vegan food sources.

B12 (a vegan form) is often added to foods like:

  • Non-dairy milks.
  • Cereal.
  • Nutritional yeast.
  • Seaweed snacks.

If you eat a lot of these, you may be fine without a supplement.

But in that case, you’d want to have regular blood tests to check your B12 levels and make sure they are healthy.

Personally, I prefer to also take a supplement, just to be on the safe side.

This is something you should discuss with your doctor, as B12 deficiency can cause very serious health issues.

The Best Fortified Vegan Foods for B12

I’ve spent a few hours looking for foods that typically have vitamin B12 added to them, and the list isn’t long.

Even in the foods in the list below, B12 is often only in some flavors. For example, the specific Kashi cereal I listed has a lot of B12, but most flavors of Kashi don’t have any.

Use this list to help you save time guessing which foods are likely to have B12. But you’ll need to check specific brands you’re interested in to see if they have B12.

Food Specific Example B12 in serving (%DV)
Nutritional Yeast Bobs Red Mill Nutritional Yeast 880%
Cereal Kashi Heart to Heart Oat Flakes and Blueberry Clusters 100%
Marmite   76%
Vegan yogurt Daiya yogurt 40%
Non-Dairy milk So Delicious almond milk 30%
Mac and cheese Daiya cheezy mac 20%
Energy bars Clif bars 10%

See my list of vegan cereals with B12 if you’d like more examples.

If you can find a good cereal, or are a fan of nutritional yeast or marmite, you can potentially get all your vitamin B12 just from food.

However, a supplement still isn’t a bad idea to be on the safe side.

Finally, regardless of which option you pick, you should see your doctor once in a while to get a blood test to check B12 levels (and a few other vitamins that are hard to get on a vegan diet).

About the author

Dale Cudmore

Your friendly neighborhood vegan from Toronto. I've spent over 6 years as a freelance nutrition writer and researcher. During this time, I've tested over 50 vegan protein powders, and over 100 other types of vegan supplements.

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