Magnesium in critical illness: Metabolism, assessment, and treatment

Abstract

Magnesium is the second most abundant intracellular cation and the fourth most common cation in the body [1]. Its importance as an essential nutrient has been recognized since 1932, when Kruse et al. [2] reported the effects of acute Mg deficiency in rats. Even recently Mg was considered the “forgotten cation” in clinical practice [3]; however, this is no longer the case [4]. Estimates of Mg deficiency range from 20% to 61% [5, 6, 7], while a recent study found that reductions in total serum Mg on admission are associated with increased mortality [8].