More than half of the body's magnesium is found in bone, the rest in cells, soft tissues, muscle and blood. If the diet is low in magnesium, it is leached from the bones. Cooking, canning and freezing destroy magnesium.
Natural Food Sources
Almonds, avocado, banana, bluefish, carp, cod, collard greens, dairy products, flounder, halibut, herring, green leafy vegetables, legumes, mackerel, milk, molasses, nuts, shrimp, swordfish, wheat germ, whole wheat bread.
Magnesium is involved in the formation of bone and teeth. It is also vital for nerve conduction and muscle contraction, plus activates enzymes that aid in the release of energy from food. It helps control blood pressure, regulate body temperature and maintain the acid-base balance in the body. Calcium and magnesium must be in proper proportion to perform their closely related body functions. For example, calcium stimulates muscles while magnesium relaxes them. Magnesium has had some success in treating migraines, asthma and diabetes.
A magnesium deficiency is not uncommon in modern diets. Processed and refined foods remove most of the magnesium, which is not replaced during enrichment. Excess calcium can cause a magnesium deficiency. Severe deficiency symptoms include muscle weakness, poor coordination, convulsions, hypertension, irritability, depression, nausea, gastrointestinal problems, hair loss, swollen gums, and calcium deposits in the kidneys, heart and blood vessels.
Toxicity is unlikely as the kidneys excrete any excess magnesium. If the kidneys are not functioning properly, magnesium toxicity symptoms may include weakness, lethargy nausea and breathing difficulties. Magnesium is often used as a laxative - a 600 mg plus dose of magnesium will lead to diarrhea.
Dietary Reference Intake
Men: 400-420 mg
Women: 310-320 mg (some researchers suggest upping this to 500 mg).