Magnesium rarely edges out other more talked about nutrients like vitamin E or calcium to make front-page news -- but it should. Magnesium plays a vital role in several hundred of your body's functions, including normal heart function, but the majority of Americans are not getting enough in their daily diets.

As many as 68 percent of Americans do not consume the daily recommended amount of magnesium, according to a government study. 19 percent do not consume even half of it.

Even the National Institutes of Health Office of Dietary Supplements (ODS) points out that, "For many people, dietary intake may not be high enough to promote an optimal magnesium status, which may be protective against disorders such as cardiovascular disease and immune dysfunction."

Magnesium's Role in Your Body

According to ODS, "Magnesium is needed for more than 300 biochemical reactions in the body." It helps to:

Maintain normal muscle and nerve function

Keep heart rhythm steady

Support a healthy immune system

Keep bones strong

Regulate blood sugar levels

Promote normal blood pressure

Maintain energy metabolism and protein synthesis

"There is an increased interest in the role of magnesium in preventing and managing disorders such as hypertension, cardiovascular disease, and diabetes," says ODS, and it is this increasing knowledge that magnesium is a major player in heart health that has peaked many scientists' interest. Highlights of studies on the topic include:

The American Heart Journal reported that patients with good magnesium levels who had undergone surgery to replace damaged coronary arteries were less likely to die or have a heart attack in the following year than those with poor magnesium levels.

A strong link was found between optimum levels of magnesium and a lowered risk of coronary heart disease, as reported in the American Journal of Cardiology.

In a study of cardiac bypass surgery patients by Duke University Medical Center researchers, those with low magnesium levels were twice as likely to experience a heart attack or die from all causes than those with normal levels.

A long-term study of men by researchers at the University of Virginia School of Medicine found that those with the lowest magnesium intake were twice as likely to have had coronary heart disease problems than those with the highest intake.

Evidence suggests that low magnesium levels increases the risk of abnormal heart rhythms, which may increase the risk of complications after a heart attack, according to ODS.

Heart disease patients who received a magnesium supplement twice a day for six months had a 14 percent improvement in exercise duration and were less likely to experience exercise-related chest pain than those who received a placebo.

"A growing body of evidence," explains Jerry L. Nadler, MD, division chief of endocrinology and metabolism at the University of Virginia, "suggests that magnesium plays a pivotal role in reducing cardiovascular risk and may be involved in the pathogenesis of diabetes itself."

Signs of Deficiency

Recommended dietary allowances for magnesium are as follows:

Boys and girls aged 1-3: 80 mg/day

Boys and girls aged 4-8: 130 mg/day

Boys and girls aged 9-13: 240 mg/day

Boys aged 14-18: 410 mg/day

Girls aged 14-18: 360 mg/day

Men aged 19-30: 400 mg/day

Women aged 19-30: 310 mg/day

Men 31 and over: 420 mg/day

Women 31 and over: 320 mg/day

Americans may have less-than-optimal magnesium levels and not experience signs of deficiency. For instance, while the recommended daily amount of magnesium for adult men is 420 mg/day, most eat only 327 mg/day. Early signs of actual deficiency include:

Loss of appetite

Nausea

Vomiting

Fatigue and weakness

More severe magnesium deficiency can result in:

Numbness and tingling

Muscles contractions and cramps

Seizures

Personality changes

Abnormal heart rhythms

Coronary spasms

Severe magnesium deficiency can lead to low levels of calcium and potassium in the blood.

How to Get More Magnesium in Your Diet

Eating a variety of magnesium-rich foods is the best way to get more of this essential nutrient. Remember that it's possible to have sub-optimal magnesium levels and not experience any actual symptoms.

"A diet rich in magnesium would benefit everyone, especially people with risk factors for type 2 diabetes, such as obesity, hypertension, elevated blood lipid levels, or a family history of diabetes," said Monika Waelti, PhD, of the Swiss Federal Institute of Technology in Zurich, Switzerland.

Some of the best food sources of magnesium include:

Whole Grains (only unrefined versions, as refined grains are typically low in magnesium)

Avocados

Squash

Almonds

Leafy Greens

Some Beans and Peas

"Hard" drinking water is also a good source of the nutrient. "Hard" water typically has a higher concentration of magnesium salts than "soft" water.

Unless your magnesium levels are very low, magnesium supplements are generally not needed.

"Increasing dietary intake of magnesium can often restore mildly depleted magnesium levels," ODS reported. So go ahead and indulge in some magnesium-rich favorites like guacamole with some whole-grain crackers, baked acorn squash, fruit salad and mixed greens. You'll be well on your way to a healthy magnesium level and, as more and more research is pointing out, a healthy heart to go along with it.