magnesium deficiency

Last reviewed 01/2018

Magnesium deficiency can result in symptoms similar to those of hypocalcaemia - muscle twitching, irritability, tetany, aggression and convulsions. There may be athetoid movements, nystagmus and a positive Babinski response.

Magnesium deficiency may cause ventricular arrhythmias such as torsade de pointes.

Treatment is with magnesium salts:

  • magnesium is given intravenously, usually as chloride or sulphate
  • serum levels must be monitored so as to prevent levels from rising above 2.5 mmol/l
  • potassium and calcium supplementation may be required
  • chronic hypomagnesaemia may be treated using magnesium oxide, 250-500 mg, by mouth, 2-4 times daily

The administration of calcium is ineffective.