Dietary minerals are the chemical elements required by living organisms, other than the four elements carbon, hydrogen, nitrogen, and oxygen 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. Dietitians may recommend that minerals are best supplied by ingesting specific foods rich with the element(s) of interest. Sometimes minerals are ingested as mineral dietary supplements, the most common being iodine in iodized salt. The dietary focus on minerals derives from an interest in supporting biochemical reactions with the required elemental components. Appropriate intake levels of certain chemical elements are thus required to maintain optimal health. According to nutritional experts, the requirements are met simply with a conventional balanced diet.