What you should know about magnesium

What you should know about magnesium

Info source:  "Healthbeat" dated 6 July 2013, a newsletter of Harvard  Medical  School. (healthbeat@mail.health.harvard.edu)

Your body needs magnesium for many tasks. It’s involved in more than 300 chemical reactions in the body. Muscles need this mineral to contract, nerves need it to send and receive messages. It keeps your heart beating steadily and your immune system strong. Most people get enough magnesium from foods such as green leafy vegetables, whole grains, beans, nuts, and fish.

Magnesium supplements are sometimes marketed as super pills that can fix a long list of ailments such as muscle tension, low energy, and trouble sleeping. But think twice before you reach for a magnesium supplement.

According to the National Institutes of Health, most older adults in the United States don’t get the proper amount of magnesium in their diets. 

But Dr. Bruce Bistrian, chief of clinical nutrition at Beth Israel Deaconess Medical Center and professor of medicine at Harvard Medical School, says magnesium deficiency is very rare. “The kidney has an extraordinary ability to reduce magnesium loss in urine, and thus achieve magnesium balance on a wide variety of intakes,” he explains.

For people who have trouble absorbing magnesium from food — such as those with celiac disease, kidney problems, alcoholism, or chronic digestive problems — supplements can be useful. 

Medicines (including some “water pills” and antibiotics) can also interfere with magnesium absorption, making a supplement necessary.

But what about the claims that magnesium supplements can improve energy, sleep cycles, and body aches? Dr. Bistrian is skeptical. “There’s no evidence to my knowledge that it would be effective for those symptoms,” he says.

If you’re concerned about low magnesium, ask your doctor for a blood test. 

To maintain a healthy magnesium level, it’s best to get the mineral from food, especially high-fiber foods including dark, green leafy vegetables, unrefined grains, and beans. 

The recommended dietary allowance (RDA) of magnesium from food is 420 milligrams (mg) per day for men ages 50 and older. 

The RDA for magnesium from supplement is lower: 350 mg per day for men and women.