Vitamin B12: Methylcobalamin vs. Cyanocobalamin

April 9, 2025

Methylcobalamin vs. cyanocobalamin—what’s the difference between these two forms of vitamin B12, and which one is better?

Cyanocobalamin is a synthetic form of vitamin B12 that may have lower absorption rates, while methylcobalamin is often preferred for its higher bioavailability.

Let’s look at the differences between these two types of vitamin B12 supplements and discover how to maintain healthy vitamin B12 levels.

What is methylcobalamin?

Methylcobalamin is a naturally occurring form of vitamin B12. This essential nutrient plays a role in red blood cell formation and nervous system functions while also supporting the health of nerve fibers and brain cells.

In addition, methylcobalamin can donate its methyl group, which is involved in DNA synthesis, neurotransmitter production, and detoxification processes.

Watch the video below to discover the importance of choosing the natural form of vitamin B12.

What is cyanocobalamin?

Cyanocobalamin is a synthetic version of vitamin B12 that contains a cyanide molecule.

Because cyanocobalamin is cheap to produce, it’s typically used in vitamin B12-fortified foods and is the most commonly supplemented form of vitamin B12.

However, cyanocobalamin has to undergo a series of complex biochemical processes to convert it into active forms of vitamin B12, such as methylcobalamin and adenosylcobalamin, that the body can utilize for cellular functions.

Not only is cyanocobalamin poorly absorbed, but it’s also linked to an increased risk of side effects, and prolonged or excessive intake may pose potential health risks.

Possible risks

Although cyanocobalamin contains only small concentrations of cyanide, the body has to detoxify and eliminate this compound.

Smokers and individuals working in mines, agriculture, and chemical manufacturing are frequently exposed to cyanide, potentially causing cyanide accumulation in the body, which could be exacerbated by taking cyanocobalamin.

Cyanide is a toxic compound that can interfere with critical cellular functions, including oxygen transport and energy production.

Research published in the Journal of Medical Toxicology investigated the adverse health effects of cyanide and concluded, “Low-dose exposures to cyanide frequently cause headache, dizziness, mild confusion, abdominal cramping, and nausea.”¹

In addition, cyanocobalamin can interact with certain medications, including antibiotics, anticonvulsants, and drugs to manage diabetes. It’s recommended to consult a healthcare professional to discuss cyanocobalamin use if you are taking prescription medications.

Methylcobalamin versus cyanocobalamin: which is better?

While both cyanocobalamin and methylcobalamin are versions of vitamin B12, methylcobalamin is generally regarded as the superior health supplement.

This has been confirmed by research published in Integrative Medicine evaluating the effectiveness of different forms of vitamin B12. The authors concluded that methylcobalamin is more effective than cyanocobalamin at maintaining vitamin B12 stores.²

“Not only is methylcobalamin cyanide-free, but it’s also significantly better absorbed and can be utilized without the need for complex conversion processes,” explains Dr. Berg.

Bioavailability

Bioavailability refers to how well a nutrient is absorbed and how readily the body can utilize it.

Cyanocobalamin isn’t well absorbed, and it requires larger doses to promote healthy vitamin B12 levels than methylcobalamin, which is generally readily absorbed by most people.

In addition, a study published in Experimental and Therapeutic Medicine found that the body retains methylcobalamin at higher rates than cyanocobalamin, which is more easily excreted via urine.³

Health benefits

Methylcobalamin is the predominant form of vitamin B12 in the body, essential for numerous physiological functions.

Vitamin B12 plays a role in vital bodily processes, including:

DNA synthesis
Red blood cell formation
Energy production
Cognitive functions
Mood regulation
Circulatory health
Vision
Skeletal integrity

Natural sources of vitamin B12

Vitamin B12 is produced by certain beneficial bacteria residing in the gut of animals, which explains why vitamin B12 is predominantly found in animal products, leaving vegetarians and vegans at risk of vitamin B12 deficiency.

Here are some of the best vitamin B12-rich food sources:

Meat
Organ meat
Poultry
Fish and seafood
Eggs
Dairy products

Nutritional yeast and certain types of algae, such as nori and spirulina, contain vitamin B12 synthesizing microbes and are among the best vegan sources of vitamin B12.

The absorption of dietary and supplemental vitamin B12 requires adequate stomach acid and intrinsic factor, a protein that facilitates the intestinal absorption of vitamin B12.

Factors including aging, use of antacids or diabetes medication, alcohol consumption, and gastrointestinal issues can greatly impact vitamin B12 absorption.

If you are concerned about your vitamin B12 status or show signs of vitamin B12 deficiency, it’s crucial to consult a healthcare provider for a thorough evaluation of your health.

Key takeaways

Methylcobalamin vs. cyanocobalamin—what’s the difference, and which one is better?

Cyanocobalamin is a synthetic form of vitamin B12 supplement that’s poorly absorbed and requires conversion into active vitamin B12.

In contrast, methylcobalamin is a naturally occurring form of vitamin B12 that the body can readily utilize. It is often chosen as an alternative to cyanocobalamin due to its higher bioavailability and lower risk of side effects.

FAQ

1. Methylcobalamin versus cyanocobalamin: which should I take?

Methylcobalamin is generally considered the better choice as it’s the active form of vitamin B12 that the body can readily absorb and utilize.
Cyanocobalamin is a synthetic form of vitamin B12 that isn’t well absorbed and requires various biochemical conversions before it can be used for physiological functions.

2. Is methylcobalamin better than cyanocobalamin?

Yes, methylcobalamin is the superior form of vitamin B12 as it’s better absorbed and more effective at maintaining optimal vitamin B12 stores than cyanocobalamin.

3. Which type of vitamin B12 is natural?

Methylcobalamin is a naturally occurring form of vitamin B12 found in the body and present in animal-derived foods such as meat, fish, seafood, and dairy.

4. Who should not take methylcobalamin?

Methylcobalamin is generally considered safe if taken in appropriate dosages.
However, individuals with preexisting health conditions should discuss the use of vitamin B12 with a healthcare provider to minimize the risk of side effects.

5. Is B12 cyanocobalamin good or bad for you?

While cyanocobalamin is considered safe, it does contain small amounts of cyanide, which is a potentially harmful compound that has to be detoxified and eliminated from the body. This leaves individuals with greater exposure to cyanide, such as miners and farm workers, at greater risk of toxicity.