What are the best vegan sources of vitamin B12, and how can we make sure we get enough?
“How do you get vitamin B12 on a vegan diet?”
This is probably the most commonly asked nutrition question around veganism, though it is not as controversial as some people might think. While it requires more planning on a vegan diet, it is possible to get sufficient B12 without eating animals.
If you’re confused about vitamin B12 and whether a vegan diet can provide enough, we’ve addressed these concerns in this blog.
What is vitamin B12 and where does it come from?
Vitamin B12 is a complex vitamin that plays a key role in keeping blood and nerve cells healthy and making DNA. Not getting sufficient amounts can lead to anemia, which can leave you feeling tired and weak.
Our bodies make B12, but we can’t use it, so we have to make sure we get enough from our diet. It can also come from microbes that live in the soil, but due to mineral depletion and soil desertification, it is no longer possible for us to get enough from the soil in which food is grown in.
Although B12 is present in animal products, it is made by the bacteria inside animals and not by the animals themselves. As modern farming practices involve keeping animals indoors for most of their lives, many farmed animals cannot obtain B12 through the soil and obtain it through supplemented feed instead.1,2
In fact, the same bacteria that make our vitamin K also make B12, but there’s a fault in our wiring. These bacteria live in the large intestine, but we can only absorb B12 via the small intestine. This means we make it after the opportunity to absorb it has passed.3 The ability to make B12 at all suggests we come from a long line of vegetarians, but that does nothing to help us modern humans get this vitamin today.
Meat and dairy are often praised as natural sources of vitamin B12, but the reality is that humans get B12 from animals because those animals are supplemented with it. The misconception that people who eat an omnivorous diet don’t rely on supplements for B12 just isn’t true. In fact, it is common for everyday foods to be fortified with vitamins and minerals in the US.
Are there any vegan B12 sources?
While some plant-based foods are fortified with vitamin B12 such as cereals, plant milks, bread, and nutritional yeast, we may not get a reliable amount from these foods alone.
As such, anyone adopting a plant-based diet should take a regular supplement of vitamin B12 alongside consuming fortified foods to be safe.
We suggest taking a daily supplement of 25-100μg or a weekly dose of 2000μg. People aged over 50 or those with conditions like celiac disease might need at least 50μg.4 By taking a supplement instead of getting B12 from farmed animals, vegans are removing the middle man.
There really is no need to fall short of this vitamin, just because somewhere along the evolutionary trail we got our intestines mixed up!
Can vegans become deficient in B12?
In the US, the recommended daily amount is 2.4mcg per day, while in the UK it is 1.5mcg.
Our bodies can store B12 for 2-4 years 5, but we must ensure we are regularly consuming enough, regardless of diet. Signs of vitamin B12 deficiency include fatigue, numbness, tingling, loss of memory, and anemia, and it can lead to nerve damage if left untreated.
According to the NHS, vitamin B12 deficiency is more common in adults aged 65 and over, as absorption decreases as we age.6 There is also an increased risk of deficiency during pregnancy.7
While vegans and vegetarians have an increased risk of deficiency if not supplementing B12, anemia – which prevents the body from absorbing B12 from our diets – is the most common cause of vitamin B12 deficiency.8
What if I take plenty of B12 but I am still deficient?
If you are low in B12, you may have a problem absorbing it, so regardless of how much you have in your diet, medical intervention may be required. This is true for everyone, vegan or not.
If you are concerned or need further advice, please see your doctor.
The importance of a well-planned diet
It is widely accepted that a well-planned vegan diet can meet our nutritional needs at all stages of life.9 However, it is crucial to ensure that we are not missing out on any essential vitamins and minerals when transitioning to a plant-based diet.
Those who are taking part in Veganuary are unlikely to develop deficiencies by eating vegan for one month, but people who are choosing to stay vegan should start supplementing vitamin B12.
Everyone who joins our 31-day email series receives daily tips, nutrition support, and free resources to help transition to a plant-based diet. Those who are concerned about deficiencies or changing their diets should consult their GP or a nutrition expert.
Helpful resources
- Veganuary’s webinar with Plant-Based Health Professionals
- The Vegan Society
- Plant-Based Health Professionals
- Dr Greger’s Daily Dozen
References
1. González-Montaña, J.-R., Escalera-Valente, F., Alonso, A.J., Lomillos, J.M., Robles, R. and Alonso, M.E. (2020). Relationship between Vitamin B12 and Cobalt Metabolism in Domestic Ruminant: An Update. Animals, [online] 10(10), p.1855. Available at: pubmed.ncbi.nlm.nih.gov [Accessed 15 Jun. 2024].
2. Wang, R., Bai, Y. and Yang, Y. (2022). Effects of dietary supplementation of different levels of vitamin B 12 on the liver metabolism of laying hens. Journal of the Science of Food and Agriculture, [online] 102(13). Available at: pubmed.ncbi.nlm.nih.gov [Accessed 15 Jun. 2024].
3. The Evolutionary Quirk That Made Vitamin B12 Part of Our Diet, Discover, Nathan H. Lents, 13 Aug 2018
4. Plant-Based Health Professionals UK. (n.d.). Micronutrients. [online] Available at: plantbasedhealthprofessionals.com [Accessed 12 Jun. 2024].
5. NHS (2019). Vitamin B12 or folate deficiency anaemia. [online] NHS. Available at: nhs.uk [Accessed 12 Jun. 2024].
6. NHS (2019). Vitamin B12 or folate deficiency anaemia. [online] NHS. Available at: nhs.uk [Accessed 12 Jun. 2024].
7. Niklewicz, A., et al (2022). The importance of vitamin B12 for individuals choosing plant-based diets. European Journal of Nutrition, [online] 62(3). Available at: pubmed.ncbi.nlm.nih.gov [Accessed 12 Jun. 2024].
8. NHS (2019). Vitamin B12 or folate deficiency anaemia. [online] NHS. Available at: nhs.uk [Accessed 12 Jun. 2024].
9. British Dietetic Association (2017). British Dietetic Association confirms well-planned vegan diets can support healthy living in people of all ages. [online] www.bda.uk.com. Available at: bda.uk.com [Accessed 15 Jun. 2024].
This content was reviewed by Claire Lynch, RD and nutritionist Rohini Bajekal from Plant-Based Health Professionals in November 2023.
