Are there non-animal sources of B12?

November 20, 2025 •

3 min read

According to the National Institutes of Health, vitamin B12 is not naturally present in plant foods unless they are fortified. This makes it a critical consideration for individuals on plant-based diets, who often ask: are there non-animal sources of B12? The answer lies in fortified foods and dietary supplements.

Quick Summary

Vitamin B12 is essential for nerve function and red blood cell production, but is naturally found almost exclusively in animal products. Reliable non-animal sources include fortified foods like nutritional yeast and plant milks, as well as oral supplements and injections, to prevent deficiency.

Key Points

Reliable sources are fortified foods and supplements: While vitamin B12 is naturally from microorganisms and found in animal products, plant-based diets can rely on foods with added B12 and oral or injectable supplements.
Fortified foods include nutritional yeast and plant milks: Excellent dietary sources of non-animal B12 include fortified nutritional yeast, plant-based milks like soy and almond milk, and certain breakfast cereals.
Supplements offer guaranteed intake: Oral B12 supplements are a dependable way to meet daily requirements, especially for those with low absorption. Higher weekly doses can also be effective.
Be cautious of unverified natural sources: Foods like spirulina, nori, and tempeh are not reliable sources of active B12 and may contain inactive analogues that interfere with absorption.
Deficiency poses a serious health risk: An adequate intake of B12 is vital to prevent serious issues like anemia, nerve damage, and neurological symptoms, which can take years to appear.
Older adults and vegans are at higher risk: Both older individuals and those on vegan diets are at a greater risk for B12 deficiency due to decreased absorption or limited natural sources.
Regular testing is recommended: For long-term vegans, regular blood tests are crucial for monitoring B12 status and ensuring proper intake.

Why Is Vitamin B12 Crucial?

Vitamin B12, also known as cobalamin, is a water-soluble vitamin that plays a critical role in several bodily functions. It is essential for nerve tissue health, red blood cell formation, and DNA synthesis. A deficiency can lead to a range of health issues, including megaloblastic anemia, nerve damage, and neurological problems. Symptoms can include fatigue, tingling sensations, weakness, and memory loss. Because the body stores several years' worth of B12, a deficiency can take a long time to develop, but the damage can be severe if left unaddressed.

The Misconception About Naturally Occurring Plant-Based B12

Some claims have circulated regarding natural B12 sources in specific plant-based foods, such as spirulina, certain seaweeds like nori, and fermented products like tempeh. However, these claims are unreliable. Many of these foods contain B12 analogues, which are compounds chemically similar to B12 but are not biologically active in humans. These analogues can interfere with the body's absorption and use of true B12, and blood tests may incorrectly show adequate levels. Experts strongly advise against relying on these foods as primary sources for this vital nutrient.

Reliable Non-Animal Sources of B12

For those on a strict plant-based diet, there are several reliable ways to ensure adequate B12 intake. The most widely accepted options are fortified foods and supplements.

Fortified Foods

Many processed foods are fortified with vitamins and minerals they don't naturally contain, including B12. These options make it easier for vegans and vegetarians to meet their daily requirements through diet.

Nutritional Yeast: This is a popular and potent source, with many brands specifically fortified with B12. It has a savory, cheesy flavor and can be sprinkled on pasta, popcorn, salads, and soups.
Fortified Plant Milks: Many plant-based milk alternatives, such as soy, almond, and oat milk, are fortified with B12. Always check the nutrition label to confirm fortification.
Breakfast Cereals: Numerous breakfast cereals have added B12, offering a convenient way to start the day with a boost of the vitamin.
Meat Substitutes: Some vegan meat alternatives, including certain soy-based products and veggie burgers, are fortified with B12.

Vitamin B12 Supplements

For many, supplements offer the most straightforward and reliable way to get enough B12.

Oral Supplements: B12 supplements are available in various forms, including tablets, capsules, and liquids. They contain different forms of B12, such as cyanocobalamin, methylcobalamin, and adenosylcobalamin. Absorption can be inefficient with large doses, so smaller, more frequent doses or a high weekly dose is recommended for better absorption.
Injections: For individuals with absorption disorders, such as pernicious anemia, injections are often prescribed by a doctor to bypass the digestive system entirely.

How to Choose the Right B12 Source

Selecting the best non-animal source depends on your dietary habits, lifestyle, and overall health. For most vegans, a combination of fortified foods and a regular supplement is the most effective strategy.


Feature	Fortified Foods (e.g., Nutritional Yeast, Plant Milks)	Oral Supplements (Daily or Weekly)	Injections (Prescription)
Convenience	Easy to integrate into daily meals. Requires checking labels.	Very convenient; dose is pre-measured.	Requires administration by a healthcare professional.
Consistency	Requires consistent consumption of multiple servings daily.	Provides a reliable, controlled dosage.	Ensures maximum absorption, bypassing digestive issues.
Cost	Part of regular grocery costs; varies by product.	Generally affordable, especially for daily tablets.	More expensive and requires medical oversight.
Absorption	Variable, depends on frequency and portion size.	Depends on dosage; high doses are absorbed less efficiently.	Most effective for those with absorption problems.
Form	Integrated into various foods.	Tablets, capsules, liquids, sublingual.	Administered via injection.

Conclusion

In summary, while there are no naturally reliable non-animal sources of B12 in an un-fortified state, people on plant-based diets can easily obtain this essential vitamin from fortified foods and supplements. Scientific evidence has consistently shown that relying on certain fermented foods or algae is ineffective due to the presence of inactive B12 analogues. By incorporating fortified items like nutritional yeast and plant milks into their diet and taking a reliable supplement, individuals can effectively prevent deficiency and support their long-term health. Regular monitoring of B12 levels through blood tests is also a crucial step for ensuring optimal intake and addressing any concerns.

For a comprehensive guide to vegan nutrition, consult The Vegan Society's official recommendations.

Frequently Asked Questions

No, vegetables do not naturally contain vitamin B12. The vitamin is produced by bacteria and is found primarily in animal products. Some claims about fermented plant foods or algae containing active B12 are unreliable.

The most reliable non-animal sources of B12 are fortified foods, such as nutritional yeast and plant milks, and vitamin B12 supplements.

Yes, nearly all vegans need to take a B12 supplement or regularly consume fortified foods to avoid deficiency. The Vegan Society recommends either consuming fortified foods two to three times a day or taking a supplement.

The National Institutes of Health recommends that adults get 2.4 micrograms (mcg) of vitamin B12 per day. Pregnant and breastfeeding individuals require slightly more.

B12 deficiency can cause anemia and lead to serious neurological and nerve damage. Symptoms may include fatigue, weakness, memory problems, and nerve tingling.

Yes, absorption can be an issue for older people and those with certain medical conditions, regardless of diet. In these cases, supplements or injections may be necessary.

B12 supplements are generally considered safe, even in higher doses, as the body absorbs only a small percentage at once. However, consulting a healthcare provider before starting any new supplement regimen is always recommended.

To check for B12 fortification in a plant milk, always read the nutrition facts label on the product's packaging.

Active B12 (cobalamin) is usable by the body, while inactive B12 analogues are chemically similar but not functional. Unreliable plant sources often contain these inactive forms, which can interfere with the body's metabolism.