Magnesium ( 1 )
Magnesium is the second most common intracellular divalent cation. Its balance in the body is controlled by a dynamic interplay among intestinal absorption, exchange with bone and renal excretion. Moreover, intracellular magnesium forms a complex with ATP and plays a key role in many important biological processes such as synthesis of cell replication, nucleic adds and proteins synthesis and is also an important cofactor in more than 300 enzymatic reactions which regulate blod pressure, nerve muscle functioning, glucose control, etc. The cationic concentration of magnesium in an adult male is around 25 g, of which 66% is located within the skeleton, 33% is intracellular and 1% is within the extracellular compartment. The recommended daily allowance (RDA) for magnesium in adults is 4.5 mg/kg/day, lower than live previous recommendation of 6-10 mg/kg/day. The daily requirement of magnesium is higher during pregnancy, lactation and following debilitating illness. Its intake depends on the magnesium concentration in drinking water and food composition. Magnesium homeostasis is maintained mainly by kidneys.