Magnesium for the prevention and treatment of cardiovascular disease

Magnesium is an essential mineral found in the body. It is naturally present in many foods and is also available as a dietary supplement.1 It serves as a cofactor in more than 300 enzymatic reactions, such as those responsible for regulating blood pressure, glycaemic control and lipid peroxidation. It is therefore also critical to the cardiovascular system.1 The adult body contains approximately 24 g of magnesium, with 50% to 60% present in bones with the rest being contained in soft tissues. Serum magnesium represents less than 1% of total body magnesium.2 In industrialised western countries, a low intake of magnesium often predisposes to a high prevalence of magnesium deficiency increasing the risk of cardiovascular events and cardiovascular death.3 This article aims to review of effect of magnesium deficiency on the cardiovascular system. In recent studies of hospitalised patients, 42% were shown to be hypomagnesaemic.4 However, physicians request magnesium testing in only 7% of these patients.4 In a study conducted among patients in the intensive cardiac care unit, 53% of patients had mononuclear cell magnesium content below the lowest normal control.5 Clinically, serum magnesium is usually measured despite the fact that less than 1% of magnesium exists extracellularly; hence, serum magnesium does not always accurately reflect total body magnesium stores. In fact, serum magnesium levels may be normal despite depletion of total body magnesium content.5 In experimental settings, total body magnesium stores can be estimated by measuring retention of an oral or intravenous magnesium load; however, measurement is cumbersome and requires a 24-hour urine collection.6 7 In many instances, intracellular levels of magnesium serve as a better indicator for total body magnesium content compared with serum magnesium levels with the most accurate test being blood mononuclear cell magnesium.8 Intracellular mononuclear magnesium …