What is the fake form of B12? Understanding Synthetic vs. Natural Cobalamin

According to some estimates, up to 40% of the US population has some form of vitamin B12 deficiency, driving many to seek supplements. This has fueled misconceptions about which forms of B12 are legitimate, with many people referring to the synthetic form, cyanocobalamin, as 'fake'.

Quick Summary

Cyanocobalamin is the synthetic form of vitamin B12, often mistaken for 'fake,' but it can be converted by the body into active B12. Naturally occurring active forms include methylcobalamin and adenosylcobalamin.

Key Points

• Cyanocobalamin is synthetic: This is the most common and cost-effective version of B12 found in supplements and fortified foods, though it is created in a lab.

• Cyanocobalamin is not inactive: The body successfully converts this synthetic form into the active coenzyme forms, methylcobalamin and adenosylcobalamin.

• Methylcobalamin is the natural form: One of the naturally occurring active coenzyme forms, methylcobalamin is found in animal-based foods.

• Pseudovitamin B12 is the true imposter: Inactive corrinoid compounds found in certain algal sources like spirulina have no vitamin activity and can interfere with true B12 absorption.

• Absorption and retention differ: While both are effective, some studies indicate differences in how the body absorbs and retains different forms of B12, a key factor for individuals with specific health needs.

• The conversion process is minor for most: For most healthy people, the conversion of cyanocobalamin is efficient enough to prevent deficiency, making cost a primary differentiator.

What are the different forms of B12?

Vitamin B12, or cobalamin, is a complex water-soluble vitamin essential for numerous bodily functions, including red blood cell production, brain health, and DNA synthesis. While many people are familiar with B12, few realize it exists in several different forms, each with unique characteristics and sources.

Cyanocobalamin: The 'Synthetic' B12

Cyanocobalamin is the most common form of vitamin B12 used in dietary supplements, multivitamins, and fortified foods. As a synthetic compound, it is created in a laboratory and not naturally found in foods. Its popularity stems from its high stability and low cost of production, making it widely accessible to consumers.

When cyanocobalamin is ingested, the body must convert it into one of the two active forms, methylcobalamin or adenosylcobalamin, before it can be used. This conversion process releases a tiny, non-toxic amount of a cyanide molecule, which is harmlessly detoxified by the body. For most healthy individuals, this conversion is efficient and effective for preventing a B12 deficiency.

Methylcobalamin and Adenosylcobalamin: The 'Natural' B12

In contrast to cyanocobalamin, methylcobalamin and adenosylcobalamin are the two coenzyme forms of B12 that are naturally active in the human body and found in animal-based foods. These are the forms your body can use directly without conversion. Methylcobalamin is primarily active in the cell plasma and is crucial for converting homocysteine into methionine, which supports nervous and cardiovascular health. Adenosylcobalamin, the other active form, is vital for energy metabolism within the mitochondria.

Pseudovitamin B12: The Truly 'Fake' Version

An even more crucial distinction should be made for pseudovitamin B12, which represents the true 'fake' or inactive forms of the vitamin. These are corrinoid compounds that structurally resemble B12 but have no biological activity in humans. These compounds are often found in certain algal supplements, such as spirulina, which is erroneously marketed as a vegan source of B12. Not only do these pseudovitamins fail to provide B12 activity, but they can also interfere with the absorption of true B12 by competing for transport proteins, potentially worsening a deficiency.

Cyanocobalamin vs. Methylcobalamin: A Comparison Table

Feature	Cyanocobalamin	Methylcobalamin
Source	Synthetic, man-made	Naturally occurring in foods
Stability	Very stable, long shelf life	Less stable, light-sensitive
Cost	Less expensive	Often more expensive
Bioavailability	Requires conversion in the body	Used directly by the body
Common Use	Supplements, fortified foods, injections	Oral supplements, often marketed as 'natural'
Target Audience	General public, cost-conscious buyers	Those with absorption issues or specific health concerns

Is One Form of B12 Superior to Another?

For most people, particularly those without specific absorption issues, both cyanocobalamin and methylcobalamin are effective at preventing or correcting a B12 deficiency. However, some individuals, especially those with certain genetic variations or neurological conditions, may benefit more from the readily available, active methylcobalamin. Recent studies suggest that methylcobalamin may also be better retained in the body and could offer additional benefits not found with the synthetic version. The choice often comes down to personal preference, cost, and specific health goals. For some, the cost-effectiveness and proven efficacy of cyanocobalamin outweigh the potential benefits of the more expensive methylcobalamin.

How to Choose the Right B12 Supplement

Choosing the right B12 supplement involves a few key considerations:

• Assess your diet: For vegans and vegetarians, a supplement is essential. Be wary of plant-based sources like spirulina that contain inactive pseudovitamin B12.
• Consider your budget: Cyanocobalamin is the most affordable and stable option, suitable for most people looking to prevent a basic deficiency.
• Evaluate specific needs: If you have a diagnosed absorption issue, have undergone gastric surgery, or have certain genetic mutations, a healthcare provider might recommend methylcobalamin or high-dose injections of hydroxocobalamin.
• Consult a professional: The best course of action is to speak with a doctor or a registered dietitian to determine the right form and dosage for your individual health profile. More information on the different forms can be found on sites like Healthline.

Conclusion

While the term 'fake' is a common misconception, the form of B12 in question is typically cyanocobalamin, a synthetic, lab-created version. Unlike inactive pseudovitamin B12 found in some algae, cyanocobalamin is perfectly usable by the human body after a conversion step. Though it differs from the natural, active methylcobalamin, it remains a stable and affordable option for preventing B12 deficiency. Ultimately, your choice of supplement should be an informed decision based on your health needs and budget, ideally made with professional medical guidance.

The Different Forms of Vitamin B12: A Comparison Table

Feature	Cyanocobalamin	Methylcobalamin	Adenosylcobalamin
Source	Synthetic, lab-made	Natural, animal-based foods	Natural, animal-based foods
Active Status	Inactive, requires conversion	Active	Active
Stability	Very stable, long shelf life	Less stable, photosensitive	Least stable, photosensitive
Cost	Typically the least expensive	Moderate to high cost	Highest cost
Common Use	Supplements, fortified foods	Sublinguals, supplements	High-end supplements

Conclusion

While cyanocobalamin is often referred to as the 'fake' form of B12, it is more accurately described as a synthetic version. Unlike truly inactive corrinoids (pseudovitamin B12), cyanocobalamin effectively prevents B12 deficiency by being converted into the active forms within the body. The decision between synthetic cyanocobalamin and natural methylcobalamin depends on individual factors like budget, health status, and specific needs. Consulting a healthcare provider is the best way to determine the ideal B12 supplement for you, ensuring optimal health and nutrient absorption. For a detailed comparison of the different B12 forms, you can read the resource on Healthline.

Frequently Asked Questions

Is cyanocobalamin harmful because it contains a cyanide molecule?

No, the minuscule amount of cyanide in cyanocobalamin is harmless and is safely detoxified by the body during conversion into the active form of B12. The amount is comparable to what is found in an apple seed.

Which form of B12 is better, methylcobalamin or cyanocobalamin?

Both are effective for treating B12 deficiency. Methylcobalamin is the natural, active form, while cyanocobalamin is synthetic and more stable. The best choice depends on individual needs, cost, and absorption ability, as some people may benefit from the pre-converted form.

Where does cyanocobalamin come from?

Cyanocobalamin is a synthetic form of B12, meaning it is manufactured in a lab. It is not naturally found in foods, unlike methylcobalamin and adenosylcobalamin, which occur naturally in animal products.

Can vegans or vegetarians rely on spirulina for B12?

No, many plant-based sources like spirulina contain pseudovitamin B12, a compound that mimics B12 but is biologically inactive in the human body. These can interfere with true B12 absorption.

What are the two active forms of B12 in the human body?

The two primary active forms of B12 in the body are methylcobalamin and adenosylcobalamin. They function as coenzymes in different metabolic pathways.

Are B12 injections usually cyanocobalamin or another form?

Historically, cyanocobalamin was often used for injections. Today, many medical professionals opt for hydroxocobalamin, a natural precursor form, due to its longer retention time in the body.

Is it possible to overdose on B12?

No, vitamin B12 is a water-soluble vitamin. Any excess amounts are typically excreted in the urine. For cyanocobalamin, specifically, no reports of overdose have been recorded.