Mecobalamin (Methylcobalamin): A Comprehensive Pharmacological and Clinical Monograph

1.0 Executive Summary

Mecobalamin, also known as methylcobalamin, is a naturally occurring and biologically active coenzyme form of vitamin B12. It is structurally distinguished from other cobalamins, such as the widely used synthetic cyanocobalamin, by the presence of a methyl group covalently bonded to its central cobalt atom. This unique structure allows it to function directly as a methyl donor in critical metabolic pathways. The primary biochemical role of Mecobalamin is to serve as an essential cofactor for the enzyme methionine synthase, which catalyzes the remethylation of homocysteine to methionine. This single reaction is pivotal for numerous physiological processes, including DNA synthesis via the folate cycle, the production of the universal methyl donor S-adenosylmethionine (SAMe), and the maintenance of the nervous system.

Clinically, Mecobalamin has long been established for the treatment of vitamin B12 deficiency, megaloblastic anemia, and various forms of peripheral neuropathy, where it exerts neuroprotective and neuroregenerative effects by promoting myelination and axonal repair. It is available globally in various formulations, including oral tablets, sublingual preparations, and injections. However, its therapeutic perception has undergone a significant transformation. Beyond its role as a nutritional supplement, recent clinical investigations have validated its pharmacological effects at ultra-high doses.