Magnesium

This mineral is the fourth most abundant in the body, essential to good health. Half of the magnesium in your body is found in bone, the rest chiefly in tissues and organs. Only 1% of magnesium is found in blood. Magnesium helps maintain normal muscle and nerve function, strengthens bones, keeps heart rhythm steady, supports the immune system, regulates blood sugar levels, and promotes normal blood pressure. A magnesium deficiency can increase the risk of heart attack and stroke.

Some studies have found that people with several types of heart problems or heart disease benefit from increased magnesium intake (in some studies the magnesium comes from food, in others from supplements or injections). However, other studies have found that supplemental magnesium doesn’t help people with heart disease live longer.

People with a diet rich in magnesium appear to have a lower risk of heart disease and stroke, and those who live in areas with hard water (high in magnesium) have a lower death rate from coronary artery disease. Foods rich in magnesium are also rich in other protective nutrients (such as potassium) and fiber, so it is difficult to separate out the effect of this single mineral. Women with osteoporosis tend to have low magnesium levels. For this reason, some dietary supplements marketed for bone health contain magnesium along with calcium and vitamin D.

Claims, purported benefits: Lowers the risk of hypertension, heart disease and stroke, helps prevent or treat diabetes, strengthens bones, prevents osteoporosis.

Bottom line: A basic multivitamin/mineral will supply all the extra magnesium you might need. Foods rich in magnesium include whole grains, nuts, beans, seeds, fish, avocados, and leafy green vegetables. If your drinking water is hard, you’ll get a fair amount of magnesium from it. Excessive magnesium (greater than the recommended levels) can cause diarrhea, nausea, cramps, muscle weakness, and heart abnormalities. People with heart disease or kidney disease should not take magnesium supplements.