What is the Difference Between Methylcobalamin and Adenosylcobalamin

The key difference between methylcobalamin and adenosylcobalamin is that methylcobalamin focuses on maintaining healthy homocysteine levels, whereas adenosylcobalamin focuses on energy formation and metabolization as it carries out most of the work in the mitochondria.

Typically, cyanocobalamin is a well-studied and reliable yet inexpensive form of vitamin B12. However, it contains a molecule of cyanide. Therefore, it is physiologically inconsequential for people. There are many alternatives that are promoted by health practitioners and supplement companies. These are coenzyme forms of vitamin B12 and are known as methylcobalamin and adenosylcobalamin. Moreover, we can find four major types of vitamin B12 that are different from each other according to the side group. These are adenosylcobalamin, cyanocobalamin, hydroxocobalamin, and methylcobalamin.

CONTENTS

1. Overview and Key Difference
2. What is Methylcobalamin 
3. What is Adenosylcobalamin
4. Methylcobalamin vs Adenosylcobalamin in Tabular Form
5. Summary – Methylcobalamin vs Adenosylcobalamin

What is Methylcobalamin?

Methylcobalamin is a form of vitamin B12 that focuses on maintaining healthy homocysteine levels. This molecule is nearly identical to cyanocobalamin, but there are slight differences between them. It contains a cobalt ion that is surrounded by a corrin ring. Methylcobalamin specifically has a methyl group attached to the cobalt ion. Moreover, this substance is a naturally occurring form of vitamin B12, whereas cyanocobalamin cannot be found naturally and is a synthetic form of vitamin B12. In addition, we can get methylcobalamin from supplements as well as from food sources such as fish, eggs, meat, and milk.

Moreover, cyanocobalamin can convert into methylcobalamin (or sometimes into adenosylcobalamin) after entering the body. Methylcobalamin is essential to many processes in the body. For example, it can get involved in the metabolism of fats and amino acids. It can also help in the formation of myelin, which can create a protective sheath around the nerve cells.

What is Adenosylcobalamin?

Adenosylcobalamin is a form of vitamin B12 that focuses on energy formation and metabolization as it carries out most of the work in the mitochondria. Technically, this molecule is known as 5’-deoxy-5’-adenosylcobalamin. However, it is also known as dibencozide, cobamine, and cobinamide.

Furthermore, this compound can participate in radical-mediated 1,2-carbon skeleton rearrangements as a cofactor. In addition, an enzyme that uses adenosylcobalamin as a cofactor is methylmalonyl-CoA mutase.

What is the Difference Between Methylcobalamin and Adenosylcobalamin?

Methylcobalamin and adenosylcobalamin are two types of vitamin B12. The key difference between methylcobalamin and adenosylcobalamin is that methylcobalamin focuses on maintaining healthy homocysteine levels, whereas adenosylcobalamin focuses on energy formation and metabolization as it carries out most of the work in the mitochondria. Moreover, the chemical structures of methylcobalamin and adenosylcobalamin are closely related to each other. In fact, the side group that is attached to the cobalt cation in methylcobalamin is a methyl group, while adenosylcobalamin contains an adenosine side group.

Below is a summary of the difference between methylcobalamin and adenosylcobalamin in tabular form for side by side comparison.

Summary – Methylcobalamin vs Adenosylcobalamin

According to the side group, there are four major types of vitamin B12 that are different from each other. These are adenosylcobalamin, cyanocobalamin, hydroxocobalamin, and methylcobalamin. In conclusion, the key difference between methylcobalamin and adenosylcobalamin is that methylcobalamin focuses on maintaining healthy homocysteine levels, whereas adenosylcobalamin focuses on energy formation and metabolization as it carries out most of the work in the mitochondria.

Reference:

1. Link, Rachael. “Methylcobalamin and Cyanocobalamin.” Healthline, Healthline Media, 12 May 2020.
2. “Coenzyme Supplements: Methylcobalamin and Adenosylcobalamin.” VeganHealth.org. Evidence-Based Nutrient Recommendations.

Image Courtesy:

1. “Methylcobalamin” By Alsosaid1987 – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “AdoCbl-ColorCoded” By Alsosaid1987 – CHEMDRAW by me (CC BY-SA 4.0) via Commons Wikimedia