Every organ in the body -- especially the heart, muscles, and kidneys -- needs the mineral magnesium. It also contributes to the makeup of teeth and bones. Most important, it activates enzymes, contributes to energy production, and helps regulate calcium levels as well as copper, zinc, potassium, vitamin D, and other important nutrients in the body.
You can get magnesium from many foods. However, most people in the United States probably do not get as much magnesium as they should from their diet. Foods rich in magnesium include whole grains, nuts, and green vegetables. Green leafy vegetables are particularly good sources of magnesium.

Atomic Number: 12
Symbol: Mg
Atomic Weight: 24.305
Discovery: Recognized as an element by Black 1775; Isolated by Sir Humphrey Davy 1808 (England)
Electron Configuration: [Ne] 3s2
Word Origin: Magnesia, a district in Thessaly, Greece
Properties: Magnesium has a melting point of 648.8°C, boiling point of 1090°C, specific gravity of 1.738 (20°C), and valence of 2. Magnesium metal is light (one-third lighter than aluminum), silvery-white, and relatively tough. The metal tarnishes slightly in air. Finely divided magnesium ignites upon heating in air, burning with a bright white flame.