Magnesium (Mg) is the fourth most abundant mineral in the body, with 60% in the bone and 40% distributed equally between muscle and non-muscular soft tissue.

Only 1% of magnesium is extra cellular. Magnesium plays a key role in at least 300 fundamental enzymatic reactions, (Particularly those that require three B vitamins (THIAMIN, RIBOFLAVIN and PYRIDOXINE), vitamins C and E. It also helps fight tooth decay by binding CALCIUM to tooth enamel) including the transfer of phosphate groups, the acylation of coenzyme A in the initiation of fatty acid oxidation, and the hydrolysis of phosphate and pyrophosphate.

Magnesium is important for such functions as the activation of amino acids, the aggregation of ribosomes, the binding of RNA to ribosome and the synthesis and degradation of DNA. It is essential for the formation of camp and other second messengers and has a key role in neurotransmission and immune function. Magnesium acts as a calcium antagonist and interacts with other nutrients, such as potassium and boron.

Magnesium has an important role in regulating the neuromuscular activity of the heart; maintains normal heart rhythm; necessary for proper calcium & Vitamin C metabolism; converts blood sugar into energy.

DEFICIENCY SYMPTOMS:
May result in calcium depletion, heart spasms, nervousness, muscular excitability, confusion; kidney stones, loose teeth.

The kidneys are extremely efficient in maintaining magnesium homeostasis; therefore, primary deficiency in healthy individuals is uncommon. Symptomatic deficiency usually is observed in the presence of a predisposing disease state, such as severe mal-absorption, chronic alcoholism, renal dysfunction, hyperparathyroidism or the use of certain medications. Clinical manifestations of deficiency are related to its role as a cofactor in enzymatic reactions, such as those requiring ATP and in regulating neurotransmitters. Hypertension, arrhythmia, neuromuscular manifestations, and personality changes occur during magnesium deficiency.

Clinical uses:
Magnesium supplementation may be appropriate in acute myocardial infarction, arrhythmias, cardiac surgery, digitalis toxicity and congestive heart failure. Magnesium toxicity is rare except in those with impaired kidney function.

Usual dietary intakes in the U.S. are about 230 and 325 mg/day for women and men, respectively. Canadian intakes are similar, but the Recommended Nutrient Intakes (RNIs) are lower (200 and 250 mg/day for adult women and men, respectively).

Food sources: Good dietary sources include legumes, whole grain cereals, nuts, dark green vegetables, and cocoa. Hard water and mineral water may be important sources of magnesium.