Cyanocobalamin is the most common and widely produced form of the chemical compounds that have vitamin B12 activity.
For example, the hadron constituents of atomic nuclei, neutrons and protons, have charges of 0 e and +1 e respectively; the neutron is composed of two down quarks and one up quark, and the proton of two up quarks and one down quark.
Quarks make up many different particles, so the hadrons are classified in two groups; those made from two quarks are called mesons, while particles made up from three quarks are called baryons. protons are made from two up quarks + one down quark; neutrons contain two down quarks + one up quark; so protons and neutrons are baryons.