An essential mineral. The chief function of magnesium is to activate certain enzymes, especially those related to carbohydrate metabolism. Another role is to maintain the electrical potential across nerve and muscle membranes. It is essential for proper heartbeat and nerve transmission. Magnesium controls many cellular functions. It is involved in protein formation, DNA production and function and in the storage and release of energy in ATP. Magnesium is closely related to calcium and phosphorus in body function. The average adult body contains approximately one ounce of magnesium. It is the fifth mineral in abundance within the body–behind calcium, phosphorus, potassium and sodium. Although about 70 percent of the body’s magnesium is contained in the teeth and bones, its most important functions are carried out by the remainder which is present in the cells of the soft tissues and in the fluid surrounding those cells.