Essential Element or Dietary Mineral
<p ><b>Dietary minerals</b> (also known as <b>mineral nutrients</b>) are the <a href="http://en.wikipedia.org/wiki/Chemical_element" title="Chemical element" >chemical elements</a> required by living <a href="http://en.wikipedia.org/wiki/Organism" title="Organism" >organisms</a>, other than the four elements <a href="http://en.wikipedia.org/wiki/Carbon" title="Carbon" >carbon</a>, <a href="http://en.wikipedia.org/wiki/Hydrogen" title="Hydrogen" >hydrogen</a>, <a href="http://en.wikipedia.org/wiki/Nitrogen" title="Nitrogen" >nitrogen</a>, and<a href="http://en.wikipedia.org/wiki/Oxygen" title="Oxygen" >oxygen</a> present in common <a href="http://en.wikipedia.org/wiki/Organic_chemistry" title="Organic chemistry" >organic molecules</a>.
Minerals in order of abundance in the human body include the seven major minerals <a href="http://en.wikipedia.org/wiki/Calcium" title="Calcium" >calcium</a>, <a href="http://en.wikipedia.org/wiki/Phosphorus" title="Phosphorus" >phosphorus</a>, <a href="http://en.wikipedia.org/wiki/Potassium" title="Potassium" >potassium</a>, <a href="http://en.wikipedia.org/wiki/Sulfur" title="Sulfur" >sulfur</a>, <a href="http://en.wikipedia.org/wiki/Sodium" title="Sodium" >sodium</a>, <a href="http://en.wikipedia.org/wiki/Chlorine" title="Chlorine" >chlorine</a>, and <a href="http://en.wikipedia.org/wiki/Magnesium" title="Magnesium" >magnesium</a>. Important "trace" or minor minerals, necessary for mammalian life, include <a href="http://en.wikipedia.org/wiki/Iron" title="Iron" >iron</a>, <a href="http://en.wikipedia.org/wiki/Cobalt" title="Cobalt" >cobalt</a>, <a href="http://en.wikipedia.org/wiki/Copper" title="Copper" >copper</a>, <a href="http://en.wikipedia.org/wiki/Zinc" title="Zinc" >zinc</a>, <a href="http://en.wikipedia.org/wiki/Molybdenum" title="Molybdenum" >molybdenum</a>, <a href="http://en.wikipedia.org/wiki/Iodine" title="Iodine" >iodine</a>, and <a href="http://en.wikipedia.org/wiki/Selenium" title="Selenium" >selenium</a> (see below for detailed discussion).
Over twenty dietary minerals are necessary for mammals, and several more for various other types of life on Earth. The total number of minerals that are absolutely needed is not known for any organism. Ultratrace amounts of some minerals (e.g., <a href="http://en.wikipedia.org/wiki/Boron" title="Boron" >boron</a>, <a href="http://en.wikipedia.org/wiki/Chromium" title="Chromium" >chromium</a>) are known that clearly have a role but the exact biochemical nature is unknown, and others (e.g. <a href="http://en.wikipedia.org/wiki/Arsenic" title="Arsenic" >arsenic</a>, <a href="http://en.wikipedia.org/wiki/Silicon" title="Silicon" >silicon</a>) are suspected to have a role in health, but without proof.
Most minerals that enter into the dietary <a href="http://en.wikipedia.org/wiki/Physiology" title="Physiology" >physiology</a> of organisms consist of simple compounds of <a href="http://en.wikipedia.org/wiki/Chemical_element" title="Chemical element" >chemical elements</a>. Larger <a href="http://en.wikipedia.org/wiki/Chemical_compound" title="Chemical compound" >aggregates</a> of <a href="http://en.wikipedia.org/wiki/Mineral" title="Mineral" >minerals</a> need to be broken down for absorption. Plants absorb dissolved minerals in soils, which are subsequently picked up by the herbivores that eat them and so on, the minerals move up the food chain. Larger organisms may also consume soil (<a href="http://en.wikipedia.org/wiki/Geophagia" title="Geophagia" class="mw-redirect" >geophagia</a>) and visit <a href="http://en.wikipedia.org/wiki/Salt_lick" title="Salt lick" class="mw-redirect" >mineral licks</a> to obtain limiting mineral nutrients they are unable to acquire through other components of their diet.
Bacteria play an essential role in the weathering of primary minerals that results in the release of nutrients for their own nutrition and for the nutrition of others in the ecological <a href="http://en.wikipedia.org/wiki/Food_chain" title="Food chain" >food chain</a>. One mineral, <a href="http://en.wikipedia.org/wiki/Cobalt" title="Cobalt" >cobalt</a>, is available for use by animals only after having been processed into complicated molecules (e.g., <a href="http://en.wikipedia.org/wiki/Vitamin_B12" title="Vitamin B12" >vitamin B12</a>), by bacteria. Scientists are only recently starting to appreciate the magnitude and role that <a href="http://en.wikipedia.org/wiki/Microorganisms" title="Microorganisms" class="mw-redirect" >microorganisms</a> have in the global cycling and formation of <a href="http://en.wikipedia.org/wiki/Biomineralization" title="Biomineralization" >biological minerals</a>.</p>