[1] Methylcobalamin features an octahedral cobalt(III) centre and can be obtained as bright red crystals.

[5][6][7] Methylcobalamin can be produced in the laboratory by reducing cyanocobalamin with sodium borohydride in alkaline solution, followed by the addition of methyl iodide.

In this pathway, methylcobalamin provides the methyl group that couples to carbon monoxide (derived from CO2) to afford acetyl-CoA.

A lack of cobalamin can lead to megaloblastic anemia and subacute combined degeneration of the spinal cord.

[10] Whether methylcobalamin administration in treating vitamin B12 deficiency is inferior or superior to other forms of cobalamin remains uncertain.