What about Vegan Vitamin B12?

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The richest food sources of vitamin B12 come from meat, fish, and milk sources.  Some vegan vitamin B12 sources are available, but for maximum vitamin B12 benefits, you would have to eat a lot of tofu to get close to 1000 mcg of vitamin B12 per week.  How can you avoid vitamin B12 deficiency on a vegan diet?


Are you getting enough vitamin B12?

The RDA for vitamin B12 is minimal- only a few mcg of B12 per day.  However, according to various scientific studies, people who receive doses upwards of 1000 mcg of vitamin B12 per week reported experiencing increased stamina, mental focus, and feelings of wellbeing.

Non-vegan sources of vitamin B12:

Clams: One 3-ounce serving of cooked clams contains 84.1 mcg of vitamin B12. 

Liver: After clams, liver is the richest source of vitamin B12.  A 3-ounce serving of cooked lamb liver contains a whopping 72.8 mcg of vitamin B12. 

Fish eggs: A 3-ounce serving of whitefish caviar provides 56.4 mcg of vitamin B12.

Mackerel: Mackerel has 19 mcg of vitamin B12 per 100 grams.


Vegan sources of vitamin B12:

Soymilk: An 8-ounce cup of soymilk provides a mere 2 mcg of vitamin B12, give or take.

Tofu: A typical serving of tofu provides 1.86 mcg of vitamin B12.

Marmite: Yeast spreads contain 0.5 mcg of vitamin B12 per 100 grams, or 0.03 per teaspoon.


Are you at risk for vitamin B12 deficiency?

There are many ways to get vitamin B12 deficiency, but they generally boil down to this:

Either you don’t eat enough foods that have vitamin B12, or you eat plenty of fish and meat, but you’re not digesting the B12.

On Becoming Vegan: Avoiding Vitamin B12 Deficiency and Others

Soy milk, fortified with B12

Reasons for not digesting vitamin B12

If your body is unable to digest vitamin B12 naturally from food, then you are at risk for vitamin B12 deficiency, even if you eat plenty of clams. 

Your only option is to supplement with vitamin B12 for life.

Factors that inhibit vitamin B12 absorption include:

  • Autoimmune disorder (Crohn’s disease, fibromyalgia, celiac disease)
  • Lack of intrinsic factor (a hormone necessary for digesting vitamin B12)
  • Drug interaction (metformin, PPIs)
  • Gastrointestinal surgery (gastric bypass)
  • Alcoholism
  • Old age

Getting extra vitamin B12

If you don’t have B12 deficiency, but you want to boost stamina, maintain a healthy weight, or enhance cognitive functioning by increasing vitamin B12 levels, then your choices are:

  • Become a seafood lover, or
  • Supplement with vitamin B12 for life.

Which B12 supplements are available?

There are different kinds of B12 vitamins, some of which require a doctor’s prescription.

  • Vitamin B12 shots: If diagnosed with vitamin B12 deficiency or pernicious anemia, then your doctor might prescribe 1000 mcg of vitamin B12 injections per week, or as needed.  A prescription is required, and many patients find that their fatigue symptoms return before the next scheduled vitamin B12 shot.
  • Sublingual vitamin B12: Vitamin B12 tablets that dissolve under the tongue are available with or without prescription.  Vitamin B12 pills are not efficient ways to access vitamin B12, and they often require you to take 3 doses throughout the day. 

    Side effects of sublingual vitamin B12 may include burning sensations on tongue and unpleasant taste.

Please tell us…

How do you get your vitamin B12- from supplements in pill form, vitamin B12 shots, or otherwise?

We’d love to hear from you- please feel free to leave your comments!

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Read more about vitamin B12 and vegan diet:

Natalie Portman Chooses B12 over Veganism

Are Vegans in France Responsible for Breast-fed Baby’s Death?

Benefits and Sources of Vitamin B12, and How to Avoid Deficiency


Top 10 Foods Highest in Vitamin B12 (Cobalamin)

Dietary Supplement Fact Sheet: Vitamin B12 Health Professional Fact Sheet


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