Magnesium: from Metabolism to Health Disorders
Regina Firantienė, Sofija Sasnauskienė, Regina Emužytė, Valerija Jablonskienė
In this review article magnesium metabolism, biochemical reactions, physiological functions, the distribution of magnesium in tissue in the body in human organism are examined.
Magnesium is the fourth most abundant cati on in the body and the second most abundant intracellular cation. Magnesium is involved in more than 300 enzymatic reactions and is essential for life. The normal adult human body contains approximately 1000 mmols (24-25 g) of magnesium. About 60-65% of the magnesium is present in bone, 35-40% is the intra - cellular magnesium, of which about 20% is in muscle and about 1-2% in the extracellular fluid. Most clintcal laboratories assess only total serum magnesium, which consists of three magnesium fractions: free ionized magnesium (active form) - 55-65%, bound to proteins - 27-30% and magnesium complexed to small anion ligands (phosphate and citrate) - 8-15%.
Magnesium plays an essential role in many functions of the body. Magnesium is essential to form chelates with important intracellular anionic-lig- ands, especially ATP. Magnesium takes part in many important metabolic processes in the organism, including energy metabolism, protein and nucleic acid synthesis, cell cycle, the binding of substances to the plasma membranes and others. It also modulates ion transport and influences intracellular calcium and potassium concentrations. It is regut ated by many hormones and depends on the cell type.
Magnesium is found in grain and vegetables, most concentrated in nuts, cocoa, dark chocolate and others.
Magnesium deficiency - hypomagnesemia is defined as a level in blood serum less than 0.5 mmol/l and hypermagnesemia - more than
1.1 mmol^l. Hypomagnesemia in organism is more prevalent that hypermagnesemia. Chronic low magnesium states have been associated with a number of chronic diseases including myocardial infarction, coronary heart disease, hipertension, osteoporosis, diabetes, asthma and many other diseases.
Keywords: magnesium, metabolism, phys i ol ogy, hypomagnesemia, hypermagnesemia, clinical effects.