Vitamin B12 metabolism

Vitamin B12 metabolism refers to the complex series of biochemical processes by which vitamin B12 (cobalamin) is absorbed, transported, converted into active forms, and utilized as a cofactor in essential enzymatic reactions. Unlike a single molecular target such as an enzyme or receptor, "Vitamin B12 metabolism" encompasses multiple proteins—including transporters like intrinsic factor and transcobalamins—and two key enzymes that require vitamin B12 as a cofactor: methionine synthase and methylmalonyl-CoA mutase. These enzymes are critical for DNA synthesis via the folate cycle and for energy production through the citric acid cycle. Disruption of this metabolic network leads to elevated homocysteine or methylmalonic acid levels—both clinically relevant biomarkers—and can result in megaloblastic anemia or neurological dysfunction. Because "Vitamin B12 metabolism" describes an entire pathway rather than a discrete molecular entity, it is not considered a therapeutic target itself but rather a collection of targets involved in cobalamin utilization[1][4][6]. **Note:** The entry "Vitamin B12 metabolism" does not refer to a specific molecule or receptor but instead denotes an interconnected metabolic pathway; therefore it should be flagged as incorrect when seeking information about individual drug targets such as receptors or enzymes.

Other names

Cobalamin metabolismCbl metabolismVitamin B12 pathwayCobalamin pathway

Supplementation restores cofactor function for methionine synthase and methylmalonyl-CoA mutase[4][6].