Methylcobalamin vs Cyanocobalamin B12

Vitamin B12, also called cobalamin, is an essential water-soluble vitamin that supports DNA synthesis, red blood cell formation, and neurological function.

B12 is naturally present in many animal-derived foods like meat, fish, and certain cheeses. Because of this, people who avoid or limit animal products may be more susceptible to low intake. Aging can also affect absorption because the body produces less intrinsic factor, a protein needed for uptake.

Common signs of low B12 include fatigue, poor balance, difficulty concentrating, changes in mood, and jaundice. A blood test is the most reliable way to confirm low levels.

Because B12 insufficiency is common, many people choose to supplement as a convenient at-home alternative to injections.

When shopping for B12, you will usually see two main forms listed on labels. These are cyanocobalamin and methylcobalamin.

Below, we break down the four forms of B12, the differences between methylcobalamin vs cyanocobalamin, and how each type functions in the body.

What are the types of B12?

There are four primary forms of B12. These are methylcobalamin, cyanocobalamin, hydroxocobalamin, and adenosylcobalamin. Most over-the-counter supplements contain either methylcobalamin or cyanocobalamin.

All B12 molecules contain cobalt at the center of a corrin ring. What differs is the group attached to that ring. Cyanide for cyanocobalamin, a methyl group for methylcobalamin, a hydroxyl group for hydroxocobalamin, and an adenosyl group for adenosylcobalamin.

Methylcobalamin

Methylcobalamin is a naturally occurring coenzyme form of B12 found in many animal-based foods. It is a form the body can use directly which makes it a strong option for supplementation.

Methylcobalamin is involved in essential processes throughout the brain, liver, and nervous system. It also participates in the methylation cycle, a process connected to functions like DNA synthesis, immune health, and hormone regulation.

It works well when paired with another form of B12 because the body also uses adenosylcobalamin. The Why Not Natural B12 liquid contains methylcobalamin along with naturally occurring hydroxocobalamin that appears during the extraction process.

Cyanocobalamin

Cyanocobalamin is a stable and cost-effective form of B12 that has been widely used in supplements and fortified foods for many years. The attached cyanide group increases stability.

It is not naturally found in significant amounts in foods. However, the body can convert cyanocobalamin into the coenzyme forms methylcobalamin and adenosylcobalamin.

Studies have shown that cyanocobalamin may have slightly higher absorption at first. Later research found that more of it is excreted in urine compared with methylcobalamin which suggests that less is retained by the body.

Individuals with certain genetic variations affecting methylation (such as MTHFR-related variations) may prefer to avoid cyanocobalamin since additional conversion is required.

Cyanocobalamin vs Hydroxocobalamin

Hydroxocobalamin is another naturally occurring form of B12 produced by bacteria in the digestive tract during the breakdown of foods. It can also be made in a laboratory process that mimics this.

It can convert to both methylcobalamin and adenosylcobalamin. It is not commonly found in over-the-counter supplements because it is more expensive and often used in clinical settings.

The Why Not Natural B12 contains a naturally occurring amount of hydroxocobalamin alongside the full listed dose of methylcobalamin.

Methylcobalamin vs Adenosylcobalamin

Adenosylcobalamin is another coenzyme form of B12. It supports cellular energy processes inside the mitochondria.

It is less stable which is why it is not commonly found in supplements. For this reason, many people take methylcobalamin along with either hydroxocobalamin, cyanocobalamin, or adenosylcobalamin to ensure coverage of both coenzyme pathways.

The naturally occurring hydroxocobalamin in the Why Not Natural B12 can convert to adenosylcobalamin in the body.

Why Not Natural B12 Contains Hydroxocobalamin

The Why Not Natural B12 liquid contains the full listed dose of methylcobalamin plus naturally occurring hydroxocobalamin. The hydroxocobalamin forms during the extraction process and is vegan, just like the methylcobalamin.

Recent laboratory testing shows that one 1 mL serving contains slightly over 50,000 mcg of methylcobalamin and an additional amount of hydroxocobalamin.

You can see the results of our most recent laboratory tests below:

This combination allows for the synergistic use of both coenzyme pathways once the B12 is metabolized.

There is currently no established upper limit for B12 intake because of its low toxicity. For general nutritional guidance, the RDI for adults is 2.4 mcg to 2.8 mcg per day. Some experts suggest higher supplemental amounts for adults depending on age and individual nutritional needs.

References

(1) Treatment of vitamin B12 deficiency: methylcobalamine? Cyanocobalamine? Hydroxocobalamin?
https://pubmed.ncbi.nlm.nih.gov/25117994/

(2) Absorption of cyanocobalamin, coenzyme B12, methylcobalamin, and hydroxocobalamin at different dose levels
https://pubmed.ncbi.nlm.nih.gov/5560708/

(3) Intestinal absorption and concurrent chemical changes of methylcobalamin
https://pubmed.ncbi.nlm.nih.gov/4696188/

(4) NIH Office of Dietary Supplements: Vitamin B12
https://ods.od.nih.gov/factsheets/VitaminB12-HealthProfessional/#h3

(5) B Vitamins: Chemistry, Metabolism, and Health Effects
https://www.sciencedirect.com/science/article/pii/B978032335868200013X

Disclaimer

The statements in this article have not been evaluated by the Food and Drug Administration. The products mentioned are not intended to diagnose, treat, cure, or prevent any disease. Please check with a doctor before starting any new supplement and to ensure the advice in this article is right for you.