Magnesium
Out of 20-28 grams of magnesium in the body, half is found in the bones.
Magnesium is required for strong, healthy bones and teeth. It helps prevent tooth decay by holding calcium in tooth enamel.
Calcium and magnesium play a very important role in muscle contraction (due to calcium flow into muscles) and muscle relaxation (due to magnesium flow into muscle). Thus magnesium deficiency can result is muscle spasms, tremors, and convulsions.

People suffering fibromyalgia and chronic fatigue have benefited from magnesium malate supplementation.
As magnesium has the properties of reducing elevated levels of C-reactive protein and thus resulting in an anti-inflammatory response.
People suffering from depression, schizophrenia, sleep disturbance and autism have all improved in health by supplementation.
magnesium helps to balance the lipid (fats) in the blood and thus help control cardiovascular disease.
Women who experience PMS symptom like lower back pain, lower abdominal pain have reversed these symptoms by taking magnesium.
Magnesium is involved in energy regulation and metabolism at the cellular level.

Things that can deplete bodies magnesium levels are alcoholism, diabetes, antibodies, diuretics, oral contraceptives and stress.

Low level of magnesium result in blood clots.

Food source
Highest: Milk and other dairy products, meat, seafood, nuts, blackstrap molasses, soybeans, seeds and wheat germ.
Good sources: oatmeal, cornmeal, and rice.

Best form of supplement:
Magnesium carbonate or magnesium oxide.

Toxicity is rare, except in individuals with kidney failure.