Endocrine disorders may cause hypomagnesemia. Primary aldosteronism decreases magnesium levels by increasing renal flow. Hypoparathyroidism and hyperthyroidism may cause renal wasting. Osmotic diuresis results in magnesium loss in the kidney. Diabetics, especially those patients with poor glucose control, develop hypomagnesemia from a glucose-induced osmotic diuresis.
Alcoholics become hypomagnesemic partially by an osmotic diuresis from alcohol.
Urinary losses have been reported to be 2-3 times control values. Miscellaneous Extracellular volume expansion, as in cirrhosis or IV fluid administration, may decrease magnesium levels. Redistribution of magnesium into cells may give lower magnesium levels. Insulin causes this effect. Excessive lactation may create a significant amount of magnesium loss.