Minerals
Dietary minerals are the chemical elements required by living organisms, other than the four elements carbon, hydrogen, nitrogen, and oxygen which are present in common organic molecules.

The term "mineral" is archaic, since the intent of the definition is to describe ions, not chemical compounds or actual minerals. Furthermore, once dissolved, so-called minerals do not exist as such, sodium chloride breaks down into sodium ions and chloride ions in aqueous solution.

Some dieticians recommend that these heavier elements should be supplied by ingesting specific foods (that are enriched in the element(s) of interest), compounds, and sometimes including even minerals, such as calcium carbonate. Sometimes these "minerals" come from natural sources such as ground oyster shells. Sometimes minerals are added to the diet separately from food, such as mineral supplements, the most famous being iodine in "iodized salt."

Dirt eating, called pica or geophagy is practiced by some as a means of supplementing the diet with elements. The chemical composition of soils will vary depending on the location, obviously.

Vitamin are not minerals, they are principally organic compounds that can contain heavy elements such as iodine, cobalt, and sulfur. The dietary focus on "minerals" derives from an interest in supporting the biosynthetic apparatus with the required elemental components. Appropriate intake levels of certain chemical elements is thus obviously required to maintain optimal health.