Magnesium: The Forgotten Electrolyte-A Review on Hypomagnesemia

Abstract

Magnesium is the fourth most abundant cation in the body and the second most abundant intracellular cation. It plays an important role in different organ systems at the cellular and enzymatic levels. Despite its importance, it still has not received the needed attention either in the medical literature or in clinical practice in comparison to other electrolytes like sodium, potassium, and calcium. Hypomagnesemia can lead to many clinical manifestations with some being life-threatening. The reported incidence is less likely than expected in the general population. We present a comprehensive review of different aspects of magnesium physiology and hypomagnesemia which can help clinicians in understanding, identifying, and treating this disorder.

Keywords: diuretics; hypomagnesemia; magnesium; proton pump inhibitors.

Figure 1

Physiology of magnesium.

Figure 2

Relation between urinary and plasma magnesium levels in a healthy subject on a magnesium-free diet (Adapted from Shils ME. Experimental human magnesium deficiency [13]) (Blue line—Plasma Magnesium, Red line—Urinary Magnesium).