What foods contain cyanocobalamin, a synthetic form of Vitamin B12?

December 30, 2025 •

4 min read

While cyanocobalamin is the synthetic form of Vitamin B12, it is the most common form added to supplements and fortified foods to prevent deficiency. Knowing what foods contain cyanocobalamin is essential for individuals on plant-based diets or with absorption issues who rely on these products for their nutritional needs.

Quick Summary

Cyanocobalamin is the synthetic variant of vitamin B12 found primarily in fortified products, not naturally in foods. This form is key for vegetarians and vegans, who rely on fortified cereals, plant milks, and nutritional yeast to meet their B12 requirements.

Key Points

Synthetic vs. Natural: Cyanocobalamin is the synthetic, manufactured form of Vitamin B12, while natural forms like methylcobalamin are found exclusively in animal products.
Fortified Food Sources: Cyanocobalamin is used to fortify products such as breakfast cereals, nutritional yeast, and plant-based milks like soy and almond milk.
Animal Product Sources: Natural vitamin B12 is found in high quantities in foods like clams, beef liver, salmon, and dairy products such as milk and yogurt.
Vegan and Vegetarian Diets: Individuals on strict plant-based diets must rely on fortified foods or supplements containing cyanocobalamin to meet their B12 needs, as plant-based foods do not naturally contain it.
Bioavailability: The body can effectively convert and absorb cyanocobalamin into the active forms it needs, making it a reliable source for supplementation.
Daily Requirements: Both fortified foods and animal products are effective sources for preventing B12 deficiency, which supports nerve health, DNA synthesis, and red blood cell formation.

Understanding Cyanocobalamin and Natural Vitamin B12

Cyanocobalamin is a synthetic and stable form of vitamin B12, also known as cobalamin, which is not found naturally in any significant quantity in food. Instead, it is produced through bacterial fermentation in a laboratory setting and is widely used in dietary supplements and for food fortification. Once ingested, the body converts cyanocobalamin into the active coenzyme forms it needs, such as methylcobalamin and adenosylcobalamin.

Conversely, naturally occurring vitamin B12, which includes methylcobalamin and adenosylcobalamin, is exclusively found in animal products. Herbivorous animals, such as cattle and sheep, obtain B12 from bacteria in their digestive systems, and this is then stored in their muscles and organs. Humans, however, do not absorb the B12 produced by bacteria in their own colon, and therefore must obtain it through diet. The distinction is vital for those following a vegan or strict vegetarian diet, as their natural food sources contain no active B12.

Fortified Foods That Contain Cyanocobalamin

For individuals avoiding or limiting animal products, fortified foods are a reliable source of cyanocobalamin to prevent deficiency. Fortification is the process of adding nutrients to foods that don’t naturally contain them. The amount of cyanocobalamin added varies by product and brand, so checking the nutrition label is crucial. Here are some of the most common fortified sources:

Fortified Breakfast Cereals: Many ready-to-eat cereals are a significant source of B12, with some providing well over 25% of the Daily Value per serving.
Fortified Plant Milks: Dairy alternatives like soy milk, almond milk, and oat milk are often fortified with cyanocobalamin to provide a vegan-friendly source of the vitamin.
Nutritional Yeast: A deactivated yeast product often used as a cheese substitute in vegan cooking. Two tablespoons can contain several times the daily recommended intake of B12 when fortified.
Meat Substitutes: Many vegan burgers and other meat alternatives are fortified with various vitamins, including cyanocobalamin, to increase their nutritional profile.
Fortified Spreads: Certain plant-based spreads and margarines may have B12 added.

Bioavailability of Cyanocobalamin

While cyanocobalamin is a synthetic form, it has excellent stability and is effectively absorbed by the body. For supplements, absorption rates are quite high for low doses, but as the dose increases, the percentage absorbed decreases significantly. Studies suggest that the body absorbs about 49% of a 1 mcg dose, but only about 1.3% of a 1000 mcg dose, as the capacity of intrinsic factor is limited. Fortunately, the remaining B12 is absorbed through a passive diffusion process. The effectiveness of cyanocobalamin supplements in raising blood B12 levels is well-documented.

Natural Sources of Vitamin B12 (Not Cyanocobalamin)

It is important to remember that these natural food sources contain methylcobalamin and adenosylcobalamin, not cyanocobalamin. The body uses both natural and converted synthetic forms for its functions.

Shellfish: Clams, oysters, and mussels are exceptionally rich sources of B12.
Organ Meats: Beef liver is one of the densest sources of vitamin B12.
Meat and Poultry: Beef, ham, lamb, and chicken contain natural B12.
Fish: Salmon, tuna, and trout are excellent sources.
Dairy Products: Milk, yogurt, and cheese provide vitamin B12.
Eggs: A large egg contains a decent amount of B12.

Comparison Table: Fortified Foods vs. Natural Sources


Feature	Fortified Foods (Contain Cyanocobalamin)	Natural Sources (Contain Methyl/Adenosylcobalamin)
Source	Produced in a lab via bacterial synthesis.	Found naturally in animal products.
Availability	Primarily found in plant-based products like cereals, yeast, and plant milks.	Exclusively in meat, poultry, fish, eggs, and dairy.
Bioavailability	Stable and well-absorbed, with absorption rates decreasing at higher doses.	Varies by food type; dairy is highly bioavailable, while eggs have lower absorption.
Dietary Suitability	Essential for vegans and vegetarians to obtain reliable B12.	Standard source for omnivores.
Bioactive Form	Converted by the body into active forms.	Already in active, usable forms.

Navigating Your Dietary Needs

Whether you need to focus on fortified foods containing cyanocobalamin depends largely on your diet. For vegans and vegetarians, incorporating a variety of fortified products or taking a supplement is necessary for optimal B12 intake. Omnivores typically get sufficient B12 from animal products, but may still benefit from fortified foods if their diet is low in meat and dairy.

Choosing a balanced diet from both natural and fortified sources, where appropriate, ensures adequate vitamin B12 intake. Regular blood tests can also help monitor levels, especially for those with conditions affecting B12 absorption. By understanding the sources and forms, you can make informed choices to support your nervous system, red blood cell production, and overall health. For more on vitamin B12, including the roles of methylcobalamin and adenosylcobalamin, see this informational article from Healthline.

Conclusion

In summary, while cyanocobalamin itself is not naturally present in foods, the body relies on it from fortified products and supplements to obtain the essential vitamin B12. Natural vitamin B12, in the form of methylcobalamin, is found exclusively in animal sources. Fortified cereals, nutritional yeast, and plant milks are critical sources of cyanocobalamin for those on plant-based diets, while meat, fish, eggs, and dairy are reliable sources of natural B12 for others. Both types contribute to preventing B12 deficiency and maintaining critical bodily functions.

Frequently Asked Questions

Yes and no. Cyanocobalamin is a specific synthetic form of Vitamin B12 (also known as cobalamin) that is commonly used in supplements and fortified foods. When it enters the body, it is converted into the active forms of the vitamin that the body can use.

As cyanocobalamin is synthetic, vegans can find it in fortified products like nutritional yeast, breakfast cereals, and plant-based milks (soy, almond, etc.). Some vegan spreads and meat substitutes are also fortified.

Natural Vitamin B12 is abundant in animal products. Top sources include shellfish (clams, oysters), beef liver, salmon, and dairy products like milk and yogurt. Meat, poultry, and eggs also provide natural B12.

For preventing a deficiency, fortified foods are a reliable and effective source of B12, especially for those who don't eat animal products. While the bioavailability can differ, the body effectively uses the cyanocobalamin from these sources once converted.

To know if a food is fortified, check the nutrition facts panel on the product label. It will list Vitamin B12 content and often state 'fortified with' or 'enriched with' somewhere on the packaging.

Yes. Methylcobalamin is a natural, active form of Vitamin B12, while cyanocobalamin is a synthetic, stable form. The body can convert cyanocobalamin into the active form, but some people, such as those with certain genetic variations, may benefit more from direct supplementation with methylcobalamin.

A deficiency in Vitamin B12 can lead to serious health issues, including anemia, nerve damage, fatigue, and neurological problems. Symptoms may develop slowly over time, making it important to maintain adequate intake.