ABSTRACT
Magnesium is a biologically essential nutrient, found to be critical for phosphorylation reactions, protein synthesis, energy transfer, and lipid and carbohydrate metabolism (1). Magnesium generally performs biological functions under circumstances where there is a need for a small, electropositive, divalent cation that will coordinate to strongly nucleophilic ligands, primarily by ionic bonding. Like Ca2, Mg2 shows strong affinity for negatively charged oxygen, which leads to crosslinking and conformational changes in proteins. Unlike Ca2, however, Mg2 does not have appreciable affinity for covalently bound oxygen, which puts it at a competitive disadvantage in spite of significantly higher intracellular concentrations. Magnesium is one of the four substantial metals in the human body, and the second most abundant metal within cells, exceeded only by potassium. Magnesium stabilizes nucleic acids, occurs in over 300 enzymes as an activator and cofactor, and like Ca is subject to similar endocrine controls. In healthy mammalian organisms homeostasis maintains plasma levels at a constant 0.9 mM (2).
