Magnesium
Last Updated on Sunday, 28 February 2010 20:56
Magnesium is needed for more than 300 biochemical reactions in the body. It helps maintain normal muscle and nerve function, keeps heart rhythm steady, supports a healthy immune system, and keeps bones strong. Magnesium also helps regulate blood sugar levels, promotes normal blood pressure, and is known to be involved in 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.
Magnesium is the fourth most abundant mineral in the body and is essential to good health. Approximately 50 percent of total body magnesium is found in bone. The other half is found predominantly inside cells of body tissues and organs. Only 1 percent of magnesium is found in blood, but the body works very hard to keep blood levels of magnesium constant.
Dietary magnesium is absorbed in the small intestines. Magnesium is excreted through the kidneys.
Recommended Intake
The Food & Nutrition Board at the Institute of Medicine of the National Academies established adequate intake for the amounts of magnesium sufficient to meet the nutrient requirements of nearly all (97-98 percent) healthy people. They are listed below in milligrams (mg) per day.
| Age | Male (mg/day) | Female (mg/day) | Pregnancy (mg/day) | Lactation (mg/day) |
|---|---|---|---|---|
| 0 to 6 months | 30 | 30 | N/A | N/A |
| 7 to 12 months | 75 | 75 | N/A | N/A |
| 1-3 years | 80 | 80 | N/A | N/A |
| 4-8 years | 130 | 130 | N/A | N/A |
| 9-13 years | 240 | 240 | N/A | N/A |
| 14-18 years | 410 | 360 | 400 | 360 |
| 19-30 years | 400 | 310 | 350 | 310 |
| 31+ years | 420 | 320 | 360 | 320 |
Sources of Magnesium
| FOOD | Milligrams (mg) per serving | Percent Daily Value* |
|---|---|---|
| Halibut, cooked, 3 ounces | 90 | 20 |
| Almonds, dry roasted, 1 ounce | 80 | 20 |
| Cashews, dry roasted, 1 ounce | 75 | 20 |
| Soybeans, mature, cooked, ½ cup | 75 | 20 |
| Spinach, frozen, cooked, ½ cup | 75 | 20 |
| Nuts, mixed, dry roasted, 1 ounce | 65 | 15 |
| Cereal, shredded wheat, 2 rectangular biscuits | 55 | 15 |
| Oatmeal, instant, fortified, prepared w/ water, 1 cup | 55 | 15 |
| Potato, baked w/ skin, 1 medium | 50 | 15 |
| Peanuts, dry roasted, 1 ounce | 50 | 15 |
| Peanut butter, smooth, 2 Tablespoons | 50 | 15 |
| Wheat Bran, crude, 2 Tablespoons | 45 | 10 |
| Blackeyed Peas, cooked, ½ cup | 45 | 10 |
| Yogurt, plain, skim milk, 8 fluid ounces | 45 | 10 |
| Bran Flakes, ½ cup | 40 | 10 |
| Vegetarian Baked Beans, ½ cup | 40 | 10 |
| Rice, brown, long-grained, cooked, ½ cup | 40 | 10 |
| Lentils, mature seeds, cooked, ½ cup | 35 | 8 |
| Avocado, California, ½ cup pureed | 35 | 8 |
| Kidney Beans, canned, ½ cup | 35 | 8 |
| Pinto Beans, cooked, ½ cup | 35 | 8 |
| Wheat Germ, crude, 2 Tablespoons | 35 | 8 |
| Chocolate milk, 1 cup | 33 | 8 |
| Banana, raw, 1 medium | 30 | 8 |
| Milk Chocolate candy bar, 1.5 ounce bar | 28 | 8 |
| Milk, reduced fat (2%) or fat free, 1 cup | 27 | 8 |
| Bread, whole wheat, commercially prepared, 1 slice | 25 | 6 |
| Raisins, seedless, ½ cup packed | 25 | 6 |
| Whole Milk, 1 cup | 24 | 6 |
| Chocolate Pudding, 4 ounce ready-to-eat portion | 24 | 6 |
*Daily Values were developed by the U.S. Food and Drug Administration to help consumers compare the nutrient contents among products within the context of a total daily diet. The Daily Value for magnesium is 400 mg. Foods providing 20 percent of more of the Daily Value are considered to be high sources of a nutrient, but foods providing lower percentages of the Daily Value also contribute to a healthful diet.
