This mineral is involved in nearly every function of the body—it is necessary for heart health, production of ATP energy for the cells, formation of bone and protein, healthy functioning of nerves and muscles, and the regulation of blood pressure and blood sugar levels. This mineral also helps maintain the acid-alkaline balance of the body and is necessary for calcium to function properly. In addition, this mineral is needed for healthy muscle, nerve and blood vessel tone and is thought to help prevent blood vessel spasms. A deficiency of this mineral can lead to numerous cardiovascular disorders, as well as anxiety, convulsions/seizures, depression, fatigue, hearing loss, impotence, insomnia, muscle cramps/spasms, neuropsychiatric disturbances, and tremors. Research indicates that levels of this mineral are chronically low among asthmatics, while migraine sufferers and individuals with kidney stones also exhibit defiencies. What is this mineral?