Magnesium

Magnesium is primarily an intracellular cation (second most abundant, 60% found in bone). In extracellular fluid, it influences neuromuscular response and irritability. A magnesium deficit may exist with little or no change apparent in serum level.

Normal Range: 1.8-3 mg/dL

increased in: Dehydration, tissue trauma, renal failure; hypoadrenocorticism; hypothyroidism. Drugs: aspirin (prolonged use), lithium, magnesium salts, progesterone, triamterene, vitamin D (renal failure). 

 

Decreased in: Chronic diarrhea, enteric fistula, starvation, chronic alcoholism, chronic liver disease, total parenteral nutrition with inadequate replacement, hypoparathyroidism (especially post-parathyroid surgery), high-dose vitamin D and calcium therapy, acute pancreatitis, delirium tremens, chronic glomerulonephritis, hyperaldosteronism, diabetic ketoacidosis, SIADH, pregnancy. Drugs: albuterol, amphotericin B, calcium salts, cisplatin, citrates (blood transfusion), cyclosporine, diuretics, ethacrynic acid.

 

Additional: Mg2+ concentration is determinated by intestinal absorption, renal excretion, and exchange with bone and with intracellular fluid.