Editing Calcium (section)

===Function===
Calcium is an [[essential element]] needed in large quantities.<ref name="lpi" /><ref name="ods" /> The Ca<sup>2+</sup> ion acts as an [[electrolyte]] and is vital to the health of the muscular, circulatory, and digestive systems; is indispensable to the building of bone in the form of [[Hydroxyapatite#Biological function|hydroxyapatite]]; and supports synthesis and function of blood cells. For example, it regulates the [[Muscle contraction|contraction of muscles]], nerve conduction, and the clotting of blood. As a result, intra- and extracellular calcium levels are tightly regulated by the body. Calcium can play this role because the Ca<sup>2+</sup> ion forms stable [[coordination complex]]es with many organic compounds, especially [[protein]]s; it also forms compounds with a wide range of solubilities, enabling the formation of the [[skeleton]].<ref name="lpi" />
<ref>
Sosa Torres, Martha; Kroneck, Peter M.H; "Introduction: From Rocks to Living Cells" pp. 1–32 in "Metals, Microbes and Minerals: The Biogeochemical Side of Life" (2021) pp. xiv + 341. Walter de Gruyter, Berlin. Editors Kroneck, Peter M.H. and Sosa Torres, Martha. {{doi|10.1515/9783110589771-001}}</ref>