Magnesium deficiency is an electrolyte disturbance in which there is a low level of magnesium in the body. It can result in multiple symptoms.[3] Symptoms include tremor, poor coordination, muscle spasms, loss of appetite, personality changes, and nystagmus.[1][2] Complications may include seizures or cardiac arrest such as from torsade de pointes.[1] Those with low magnesium often have low potassium.[1]
Causes include low dietary intake, alcoholism, diarrhea, increased urinary loss, poor absorption from the intestines, and diabetes mellitus.[1][4][5] A number of medications may also cause low magnesium, including proton pump inhibitors (PPIs) and furosemide.[2] The diagnosis is typically based on finding low blood magnesium levels (hypomagnesemia).[6] Normal magnesium levels are between 0.6 and 1.1 mmol/L (1.46–2.68 mg/dL) with levels less than 0.6 mmol/L (1.46 mg/dL) defining hypomagnesemia.[1] Specific electrocardiogram (ECG) changes may be seen.[1]
Treatment is with magnesium either by mouth or intravenously.[2] For those with severe symptoms, intravenous magnesium sulfate may be used.[1] Associated low potassium or low calcium should also be treated.[2] The condition is relatively common among people in hospitals.[2]
Deficiency of magnesium can cause tiredness, generalized weakness, muscle cramps, abnormal heart rhythms, increased irritability of the nervous system with tremors, paresthesias, palpitations, low potassium levels in the blood, hypoparathyroidism which might result in low calcium levels in the blood, chondrocalcinosis, spasticity and tetany, migraines,[7] epileptic seizures,[8] basal ganglia calcifications[9] and in extreme and prolonged cases coma, intellectual disability or death.[10] Magnesium plays an important role in carbohydrate metabolism and its deficiency may worsen insulin resistance, a condition that often precedes diabetes, or may be a consequence of insulin resistance.[11]
People being treated on an intensive care unit (ICU) who have a low magnesium level may have a higher risk of requiring mechanical ventilation, and death.[12]
Magnesium deficiency may result from gastrointestinal or kidney causes. Gastrointestinal causes include low dietary intake of magnesium, reduced gastrointestinal absorption or increased gastrointestinal loss due to rapid gastrointestinal transits. Kidney causes involve increased excretion of magnesium. Poor dietary intake of magnesium has become an increasingly important factor – many people consume diets high in refined foods such as white bread and polished rice which have been stripped of magnesium-rich plant fiber.[13]