Vitamin B12 is a water soluble, organic compound and essential nutrient involved in the everyday functioning of the nervous system and the brain.
Vitamin B12 is involved in the preservation and regeneration of the myelin shealth - the protective fatty layer that acts as an insulator in nerve axons.
Animals store vitamin B12 in liver and muscle and therefore eggs, milk, meat, liver are sources of the vitamin.
Problems in metabolism of vitamin B12 lead to "persistent" lack of energy to perform every day tasks.
The genes and pathways highlighted above describe several routes through which genes and metabolites involved in B12 metabolism are interconnected.
Central B12 metabolism nodes include folate metabolism and the synthesis of the citric acid cycle intermediates and succinyl-CoA, cyanocobalamin into methylcobalamin conversion, tyrosine nitration and riboflavin pathways.
Proteins on this pathway have targeted assays available via the [CPTAC Assay Portal](https://assays.cancer.gov/available_assays?wp_id=WP1533).