Magnesium

Magnesium is vital for many metabolic functions including activation of enzymes for proper metabolism of protein and carbohydrates for energy production. It is a constituent of bones and teeth and is important for the metabolism of phosphorus, calcium, potassium, sodium, B-complex vitamins, and vitamins C and E. It is necessary in the production of testosterone and progesterone and essential for normal heart beat, nerve transmission, bone growth, body temperature, and arterial health. Magnesium, in proper balance with calcium, is important for neuromuscular contractions and is vital for DNA and RNA production and repair. It appears to be helpful in stroke prevention. Magnesium is absorbed in the small intestine and vitamin D is necessary for proper utilisation of the mineral.

FOOD SOURCES

Nuts, pulses, whole grains and seeds, green leafy vegetables, brewer's yeast, seafood, cocoa, figs, garlic, tofu.

SUPPLEMENTATION

Magnesium ions are absorbed at around 30-40% efficiency from any soluble magnesium salt, but elemental magnesium salts (sulphate, citrate, chloride etc) can give rise to intestinal discomfort and can have a laxative effect. Absorption from insoluble salts such as magnesium oxide (present in many antacids) is low at around 4%, declining with age. Useful sources include magnesium amino acid chelate, magnesium ascorbate, magnesium gluconate.

Vitamin D assists in the uptake of magnesium. Do not take magnesium supplements without consulting a doctor if you any of the following apply: kidney failure, heart block, ileostomy, chronic constipation, colitis or diarrhoea, symptoms of appendicitis, diuretics, chemotherapy, digitalis drugs, antibiotics, heavy drinker, had a heart attack, intestinal or stomach bleeding. Do not take magnesium supplements during pregnancy or nursing without the advice of your doctor.

SIGNS OF DEFICIENCY

Bruxism, predisposition to cardiac-rhythm abnormalities, confusion, convulsions, diarrhea, hallucinations, irritability, loss of appetite, nausea, nervousness. Chronic deficiency may cause cardiovascular problems, skin disorders, tachycardia, tremors, uncontrolled muscle contractions, vomiting. Deficiency common in Western countries.

SIGNS OF TOXICITY

Very high intake may lead to drowsiness, lethargy, nausea, vomiting, hypotension, muscle weakness, sluggishness, slow breathing, stupor, and coma. Chronic excessive intake (e.g. from antacids) can lead to deficiencies of other elements.

DAILY MINIMUM REQUIREMENT

300-400 mg approx. (do not exceed 300 mg/day supplementation).