Magnesium: The Neglected Electrolyte? A Clinical Review

Abstract

Magnesium, Mg2+, is the second most abundant\rintracellular cation after potassium and the fourth most abundant in the body. It\rwas first isolated in 1808 by the English chemist, Sir Humphrey Davy. Magnesium\ris essential to numerous biochemical reactions. It modulates key physiological\rprocesses such as metabolic biochemistry, nucleic\racid synthesis, receptor-binding and ion flux. The western diet falls short of\rthe recommended daily allowance of 4.5 mg/Kg/day and important dietary sources\rare seeds, grains, nuts and green vegetables. It is used as a therapeutic agent\rin a broad range of pathologies: neurological,\rcardiovascular, respiratory, gastrointestinal and obstetric.\rThe pharmacokinetics and pharmacodynamics of magnesium, as a drug, are not well\runderstood. Despite its fundamental importance to\rhuman physiology, it remains an electrolyte that is not routinely measured as\rpart of the “urea & electrolytes” test and is the most overlooked electrolyte\rdeficiency in hospital inpatients. This review will summarise the importance of\rmagnesium homeostasis, its pharmacological effects and clinical applications.