ABSTRACT
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 Magnesium Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138 Magnesium and Musculoskeletal Health . . . . . . . . . . . . . . . . . . . . . . . . . . . 138 Magnesium Homeostasis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 Diet and Magnesium Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 Nondietary Factors and Magnesium Status . . . . . . . . . . . . . . . . . . . . . . . . . 141 Calcium and Magnesium Balance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 Diet and Calcium-Magnesium Balance . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 Identification of Magnesium Deficits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 Magnesium Supplements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 Caution: Excess Magnesium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 Acknowledgment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
Magnesium is the fourth most abundant mineral in the body and, after potassium, the second most plentiful intracellular cation. Intimately involved in multiple aspects of metabolism, magnesium is a required cofactor for over 300 regulatory enzymes.1 Besides its requirement for specific enzymes, magnesium is involved indirectly in all enzymatic processes, as adenosine triphosphate (ATP) must be complexed to magnesium to be metabolically available.2 Magnesium is required for carbohydrate, fat, and protein ultilization.3,4 During cell replication, magnesium is required to maintain an adequate supply of purine and pyrimidine nucleotides necessary for DNA and RNA production.4 Virtually all hormonal reactions are magnesium dependent.5 Through its association with sodium, potassium, and calcium, magnesium is closely involved in maintaining cellular electrolyte balance and adequate amounts of magnesium are needed to maintain normal levels of potassium.5 It is required to maintain voltages across cell membranes and for the transfer of electrical impulses in neurons and muscle cells.6
