Essentiality and Deficiency

Essentiality and Deficiency

Magnesium is a cofactor of manyenzymes. In the glycolytic cycle, there are seven key enzymes thatrequire divalent magnesium. Magnesium-containing enzymes are also involved in the citric acid cycle and in beta oxidation of fatty acids. Deficiency may occur as a complication of various disease states such as malabsorption syndromes, renal dysfunction, and endocrine disorders. Magnesium deficiency in humans causes neuromuscular irritability, frank tetany, and even convulsions. Magnesium deficiency induces an inflammatory syndrome, and is a risk factor for diabetes mellitus, hypertension, hyperlipidemia, and ischemic heart diseases. Supplementation of magnesium, either by intravenous or oral administration, is beneficial.

Toxicity

In industrial exposures, no ill effects are produced with a twofold increase in serum magnesium, although concurrent increases occur in serum calcium. Inhaled freshly generated magnesium oxide can cause metal fume fever, similar to that caused by zinc oxide. In nonoccupationally exposed individuals, toxicity can occur when magnesium-containing drugs, usually antacids, are ingested chronically by persons with serious renal failure. The toxic effects may progress from nausea and vomiting to hypotension, electrocardiograph abnormalities, central nervous system effects, coma, and systolic cardiac arrest. Magnesium toxicity can sometimes be counteracted with calcium infusion.