Types of Vitamin B12 Supplementation

    Vitamin B12, also called cobalamin, can include hydroxocobalamin, methylcobalamin, cyanocobalamin, and adenosylcobalamin. Hydroxy, methyl, and adenosyl are all forms of B12 that are used directly for reactions in the body.

 

HYDROXOCOBALAMIN

Hydroxocobalamin is a naturally occurring form of B12. It is converted into both bioactive coenzyme forms of B12—methyl and adenosylcobalamin. Therefore, we can think of hydroxocobalamin as a continuous supply needed to create them. Hydroxocobalamin also has another special function before it is converted into the active forms: as a free radical scavenger. Carriers of the TCN2 gene polymorphism may benefit from this form of supplementation. This gene encodes transcobalamin II (TCII), a member of the vitamin B12-binding protein family. This plasma protein binds to cobalamin and mediates its transport from the intestine to the blood cells. Variants in the gene can reduce the absorption capacity of cobalamin (vitamin B12).

 

METHYLCOBALAMIN

Methylcobalamin works in conjunction with active folate (methylfolate) to create methyl groups and as such is heavily involved in the prevention of anemia, cardiovascular risk and all things related to the nervous system and DNA.

Variants in the MTR gene can result in significantly increased gene activity and consequently increased use and deficiency of methylcobalamin. MTR activity can be supported by supplementation of B12 in the form of methylcobalamin.

The composite status of MTR and MTRR is also important, as MTRR helps to recycle B12 for use by MTR. MTRR (methionine synthase reductase) regenerates MTR through a methylation reaction that uses SAMe as a donor. The MTRR gene also supports MTR activity by recycling and converting vitamin B12 to its methylated form. Variants in MTRR can result in downregulation of the gene’s activity and reduce its effectiveness in supporting MTR and contribute to elevated homocysteine ​​levels.

 

ADENOSYLCOBALAMIN

Adenosylcobalamin is used in the mitochondria of all our cells to produce Succinyl-CoA which generates ATP, the universal energy provider in the human body. MUT is a mitochondrial enzyme that converts methylmalonyl Co-enzyme A to succinyl-Co-enzyme A requiring adenosylcobalamin (adenosyl-B12) as a cofactor. Succinyl-CoA is an important enzyme in the Krebs cycle and is crucial for the synthesis of heme, cytochrome P450s and nucleotides. The risk genotype of the MUT gene is associated with decreased enzyme activity, resulting in impaired ability to convert methylmalyonyl CoA to succinyl-CoA, so adenosylcobalamin supplementation may be beneficial in these cases.

 

CYANOCOBALAMIN

Cyanocobalamin is a synthetic form of cyanide, which is used in cheaper supplements. So when you take cyanocobalamin, your body must first convert it to hydroxocobalamin in order to use it, and then it must find a way to get rid of the toxic cyanide molecule. Cyanocobalamin is used because it is the much cheaper form of B12.