The study of metals and metal species, and their interactions, transformations, and functions in biological systems.

Some scientific researchers believe that there is a need to know more and more about the original form of metal elements and their interactions with other chemical or biochemical entities.

For example, arsenic is regarded as toxic, but this chemical is primarily associated with inorganic forms; such as, arsenite while arsenobetaine is an organic chemical form of arsenic, which exists normally in seafood and is considered to be non-toxic.

This is why it is necessary to study all of the elements, regardless of metals, nonmetals, or metalloids, in biological systems to determine their influences on animals and humans.