Magnesium

Magnesium, an abundant mineral in the body, is naturally present in many foods, added to other food products, available as a dietary supplement and present in some medicines (such as antacids and laxatives). Magnesium is a cofactor in more than 300 enzyme systems that regulate diverse biochemical reactions in the body, including protein synthesis, muscle and nerve function, blood glucose control, and blood pressure regulation. Magnesium is required for energy production, oxidative phosphorylation, and glycolysis. It contributes to the structural development of bone and is required for the synthesis of DNA, RNA, and the antioxidant glutathione. Magnesium also plays a role in the active transport of calcium and potassium ions across cell membranes, a process that is important to nerve impulse conduction, muscle contraction, and normal heart rhythm.

Magnesium is also an important mineral in bones and has the role of increasing the absorption of calcium by the bones.  Magnesium deficiency impairs bone-building and leads to calcium being deposited in soft tissue rather than the bone. If there is a deficiency of magnesium, a deficiency of calcium develops even if supposedly adequate calcium supplementation is taken.

Magnesium is widely distributed in plant and animal foods and in beverages. Foods that are high in the mineral magnesium include green leafy vegetables, such as spinach, legumes, nuts, seeds, and whole grains, which are good sources. In general, foods containing dietary fiber provide magnesium. Magnesium is also added to some breakfast cereals and other fortified foods. Some types of food processing, such as refining grains in ways that remove the nutrient-rich germ and bran, lower magnesium content substantially.