Magnesium, an essential mineral for maintaining good health, is needed for the body’s muscle, nerve, heart, and immune system functions. It also helps maintain proper blood sugar levels and blood pressure. There are many different sources of magnesium; it is found in many foods, especially certain nuts, legumes, vegetables, and grains. Those concerned about their magnesium intake also can take dietary supplements.
A variety of nuts are good sources of magnesium. According to the U.S. National Institutes of Health’s Office of Dietary Supplements, 1 ounce of dry-roasted almonds contains 80 mg of magnesium. One ounce each of dry-roasted cashews has 75 mg and mixed nuts contains 65 mg. Peanuts (50 mg per ounce) and peanut butter (50 mg per 2 tablespoons) also are among the good sources of magnesium.
Soybeans and spinach have the highest magnesium levels among vegetables. One half cup of frozen, cooked spinach or cooked soybeans each provide 75 mg of magnesium. Other sources of magnesium include a medium baked potato with skin (50 mg), a 1/2 cup of cooked black-eyed peas (45 mg), and a 1/2 cup of pureed avocado (35 mg).
Fish is another source of magnesium. Halibut has one of the highest magnesium levels at 90 mg per 3 ounces cooked. One hundred fifty grams of crab nets 50 mg of magnesium, while 10 steamed scallops, six prawns, and 12 oysters all have 40 mg of magnesium each.
Food is the best source of magnesium, but people who do not eat enough magnesium-rich foods often turn to a dietary supplement. The Institute of Medicine of the National Academy of Sciences recommends varying levels of magnesium daily intake depending on age and gender. Children of both genders should reach 80 mg a day between 1 and 3 years old, 130 mg between 4 and 8 years, and 240 mg between 9 and 13 years. Men 14 to 18 years should consume 410 mg daily, 400 mg daily for 19- to 30-year-olds, and 420 mg for men 31 years and older. For women, the recommendations are 360 mg daily between 14 and 18 years, 310 mg between 19 and 30 years, and 320 mg for women 31 and older.