If active transport fails, dietary requirements rise sharply, analogous to calcium absorption problems. Magnesium is widely distributed in plant and animal foods, so that deficiency usually only occurs with impaired absorption, malnutrition, alcoholism, or diuretic use. Deficiency symptoms begin with nausea, loss of appetite, edema, fatigue, and progress to major neurological symptoms- tremors, disordered movement, convulsions, and coma. Magnesium and calcium deficiency may predispose to sudden death from cardiac arrhythmia, and ironically, is most likely to occur with diet and diuretic therapies for hypertension and heart disease. Magnesium deficiency also occurs in chronic alcoholism from Mg loss in the urine, exacerbated by low dietary intake, gastrointestinal losses with diarrhea or vomiting.
Osteoporosis is prevalent in the alcoholic population.
Serum concentrations of vitamin D are also low. Hypomagnesemia in alcoholics may also contribute to increased cardiovascular disease by enhanced platelet aggregation which can be corrected with Mg therapy. Mg inhibits the synthesis of thromboxane A2 and 12-hydroxyeicosatetraenoic acid, eicosanoids thought to be involved in platelet aggregation. Magnesium supplementation should be considered for every patient on diuretics, and patients with cardiovascular diesase - hypertension and increased risk of heart attacks. Magnesium replacement is essential for alcoholics and increased doses are given druing withdrawal from alcoholic beverage intake.