If you love fresh green vegetables, you are not likely to run low on this essential mineral. And it seems a healthy body knows just how much to use; when you consume a lot of high-magnesium foods, the body absorbs less. Conversely, when you eat few magnesium-rich foods, your body absorbs more of the magnesium present in the food.

An important benefit of magnesium is its role in helping to prevent heart attacks and the build up of fatty plaque on the walls of blood vessels. It also plays an important role in the contraction of muscles. It has also reportedly been used in some cases to successfully treat neuromuscular disorders, PMS, depression and sensitivity to noise. And despite the widespread belief that it's calcium that our teeth need to grow strong to resist decay, it's actually magnesium which does the hard work - without it, calcium forms only a soft enamel.

Functions:

Widely distributed in the body, especially in the bones and teeth. Magnesium is involved in the formation of proteins, fats, complex carbohydrates, and in the transmission of nerve impulses and muscle contraction.

Deficiencies:

While deficiencies are rare, they can occur with diarrhoea and vomiting, with high blood pressure and with excessive alcohol intake.

Sources:

Cereals, green vegetables, especially spinach, as well as potato, sweetcorn, nuts and pulses. Absorption from plant foods is better than from animal foods.

Interestingly:

The hardness of the your local water supply will also affect your magnesium intake. A hard water supply will offer a higher magnesium content.

RDI:

Around 300 mg.

Source: Growcom's formulaforlife - choose good health & happiness.