Magnesium is found in many foods, including nuts, seeds, leafy greens, legumes and whole grains. The National Institutes of Health rates the magnesium levels of food by milligrams per serving. According to its list, the top sources are almonds, spinach, cashews, peanuts and shredded wheat cereal. Other notable sources are soy in the form of milk or edamame, black beans, whole wheat bread, avocados and baked potatoes with the skin.
Dark chocolate and dairy products, such as milk and yogurt, are also good sources of magnesium. It is also found in smaller concentrations in chicken, beef and fish. Magnesium is also present in fortified cereals. It can be taken as a supplement, preferably in a form that dissolves well in liquid.
Many people are deficient in magnesium, which is a vital nutrient for the support of energy levels and the health of the heart and blood vessels. It may help to prevent heart attacks, strokes, high blood pressure and diabetes. Magnesium also contributes to bone health and may lower the risk of osteoporosis. Severe magnesium deficiency is rare and usually only occurs in people who have digestive difficulties, kidney disease or parathyroidism or in those who take anti-cancer drugs or antibiotics, or suffer from alcoholism.