Magnesium deficiency is common in people taking "potassium-depleting" prescription diuretics. Taking too many laxatives can also lead to deficiency. Alcoholism, severe burns, diabetes, and heart failure are other potential causes of deficiency. In a study of urban African-American people (predominantly female), the overall prevalence of magnesium deficiency was 20%. People with a history of alcoholism were six times more likely to have magnesium deficiency than were people without such a history.199 The low magnesium status seen in alcoholics with liver cirrhosis contributes to the development of hypertension in these people.200
Almost two-thirds of people in intensive care hospital units have been found to be magnesium deficient.201 Deficiency may also occur in people with chronic diarrhea, pancreatitis, and other conditions associated with malabsorption.
Fatigue, abnormal heart rhythms, muscle weakness and spasm, depression, loss of appetite, listlessness, and potassium depletion can all result from a magnesium deficiency. People with these symptoms should be evaluated by a doctor before taking magnesium supplements.
As previously mentioned, magnesium levels have been found to be low in people with chronic fatigue syndrome.
Deficiencies of magnesium that are serious enough to cause symptoms should be treated by medical doctors, as they might require intravenous administration of magnesium.202