B-12MG

Vitamin B12, also known as cobalamin, is a water-soluble vitamin essential for DNA synthesis, red blood cell formation, and nervous system function  Unlike peptides, which are chains of amino acids linked by peptide bonds, B12 is a coordination complex with a central cobalt atom bound to a corrin macrocycle and additional ligands such as methyl, adenosyl, or cyanide groups depending on the form (methylcobalamin, adenosylcobalamin, cyanocobalamin),. This structure makes it the most chemically complex vitamin and the only one containing a metal ion.