Magnesium is the element in the periodic table with the chemical symbol Mg. The mineral got its name from the Greek city, Magnesia, where large deposits were found in a substance called magnesium carbonate, a magnesium salt with laxative properties. Magnesium carbonate and another magnesium compound, magnesium sulfate, are still used as laxatives. However, that is by no means the primary function of magnesium. Though not as publicized for its multiple roles in keeping us healthy as other vital minerals like sodium, calcium, and potassium, magnesium is likewise an essential component of our daily diet. In fact, the proper metabolism of many other nutrients is dependent on the presence of a sufficient concentration of magnesium in the bloodstream, bones, and tissues.
Magnesium is the fourth most abundant mineral in the body but second only behind the potassium intercellularly. Approximately 60% of the 20-28 grams of magnesium in the human body is found in bone, with most of the remainder of soft tissues and only 1% in extracellular fluids. The brain and heart both contain significant amounts of magnesium.
Normal serum levels of magnesium fall in the range of about 1.7-2.5 mg/dL. Usually, unless some other underlying condition is interfering with either the absorption of the needed required amount of magnesium or elimination of the excess, these levels are maintained. The human body is remarkably efficient at keeping the concentration of magnesium in the blood from deviating much regardless of the day to day variations in intake.
Maintaining this homeostasis not only of the absolute levels of magnesium but of the ratio of the concentration of magnesium in the blood to that of other essential minerals such as calcium is critical. Serious, even life-threatening, health problems can result otherwise. Since the body cannot manufacture magnesium on its own, it depends on receiving the necessary amounts of it in the diet. Fortunately, the ready availability of magnesium in a wide variety of foods, as well as in supplement form when needed, makes the potentially dire consequences relating to either pronounced deficiency or toxicity of magnesium uncommon.