HE-438, Reprinted November 1996. Recommended for Extension use by Barbara Struempler, Extension Nutritionist, Professor, Auburn University. Originally prepared by J. Yvonne Jackson, former Nutrition Specialist.

Minerals

Over 17 minerals are known to be needed by the body -- some in relatively large amounts, such as calcium and phosphorus; others in small amounts, like iron and zinc. Some minerals, such as lead, mercury, and cadmium, are actually harmful to your body.

Minerals have two general functions -- building and regulating. Their building functions affect your bones, teeth, and all soft tissues. Their regulating functions include a wide variety of systems, such as the beating of your heart, the clotting of your blood, maintaining nerve responses, and transporting oxygen from your lungs to the tissues. Along with protein, carbohydrates, fats, water, and vitamins, you must have minerals to build a strong body and to carry on all its delicate life processes.

Mineral deficiencies are not as common today as they once were. However, many people, especially women, have a low blood level of iron. This condition is known as iron deficiency anemia.

Iron is an important part of the compounds necessary for taking oxygen to the cells and for making use of the oxygen when it arrives. The only way a significant amount of iron can leave the body is through a loss of blood. This is why people who are forming more blood have the greatest need for dietary iron. Women of childbearing age, pregnant women, and growing children are most likely to suffer from iron-deficiency anemia because of their higher needs.

Even though minerals are required for health, they can be harmful if you get too much. For example, if all the potassium your body needs in one day were taken in a single dose, severe illness could result. Other minerals could cause illness if you took as little as twice the amount required for good health. Taking too much of one essential mineral may also affect your body's use of other minerals.

There are two classes of dietary minerals -- macroelements, the ones we need relatively more of, and trace, the ones we need in small amounts. The body does not make minerals. They all must come from food. Minerals are found in almost all foods. The following list shows the function of each essential mineral, the amount you should get daily, and the best food sources. The USDA Dietary Guidelines for Americans recommend that you eat a wide variety of foods to get the minerals you need.

Macroelements

Calcium - Needed to build bones and teeth. It also helps regulate nerves, muscle tone, and blood clotting.
Amount recommended: 800 mg* for adults.
Sources: Milk, cheese, ice cream, kale, turnip greens, and broccoli.

Phosphorus - Needed to build bones and teeth. Helps your body get energy from food.
Amount recommended: 800 mg* for adults.
Sources: Milk, cheese, peanuts, meat, eggs, and poultry.

Magnesium - Needed to build bones and teeth. Helps your body use carbohydrates. Helps maintain muscle and nerve irritability.
Amount recommended: 300 mg* for women; 350 mg* for men.
Sources: Whole-grain cereals, nuts, green leafy vegetables, beans, meat, poultry, and fish.

Sodium - Helps control water balance. Regulates nerve impulses and muscle contractions.
Amount recommended: 1110 to 3300 mg* is considered adequate and safe. Too much can be harmful.
Sources: Salt, cheese, milk, shellfish, meat, and eggs.

Potassium - Helps control water balance. Helps regulate nerve impulses, muscle contractions, and heart rhythm.
Amount recommended: 1875 to 5625 mg* is considered adequate and safe. Too much can be harmful.
Sources: Meat, milk, and fruits.

Chlorine - Aids digestion.
Amount recommended: 1700 to 5100 mg* is considered adequate and safe. Too much can be harmful.
Sources: Salt, seafoods, milk, meat, and eggs.

Sulfur - Is a part of protein tissue, hair, and nails.
Amount recommended: Your body's need for sulfur is satisfied by eating protein foods.
Sources: Meat, fish, poultry, eggs, milk, cheese, legumes, and nuts.

Trace Elements

Iron - Is a necessary part of hemoglobin. Helps your body get energy from food.
Amount recommended: 18 mg* for women up to age 50; 10 mg* for women over age 50 and for men.
Sources: Liver, meat, egg yolk, whole or enriched grains, dark green vegetables, dark molasses, dried beans, shrimp, and oysters.

Manganese - Is a part of bones.
Amount recommended: 2.5 to 5 mg* is considered adequate and safe. Too much can be harmful.
Sources: Whole grains, nuts, and legumes.

Iodine - Regulates energy used by your body.
Amount recommended: 150 mcg* for adults.
Sources: Iodized table salt and seafoods.

Copper - Helps your body absorb and use iron in making hemoglobin. Also helps your body get energy from food.
Amount recommended: 2 to 3 mg* is considered adequate and safe. Too much can be harmful.
Sources: Liver, shellfish, whole grains, legumes, and nuts.

Fluorine - Increases the resistance of your teeth to decay.
Amount recommended: 1.5 to 4.0 mg* is considered adequate and safe. Too much can be harmful.
Sources: Fluoridated drinking water and beverages made from fluoridated water.

Zinc - Helps regulate many of your body's processes.
Amount recommended: 15 mg* for adults.
Sources: Seafoods, meats, fish, and whole grains.

Selenium - Works with vitamin E.
Amount recommended: 0.05 to 0.2 mg* is considered adequate and safe. Too much can be harmful.
Sources: Meat, seafoods, and whole grains.

Molybdenum - Helps regulate many of your body's processes.
Amount recommended: 0. 15 to 0.5 mg* is considered adequate and safe. Too much can be harmful.
Sources: Legumes, cereal grains, green vegetables, and organ meats.

Cobalt - Is a part of vitamin B-12.
Amount recommended: 3 to 5 mcg* of vitamin B-12.
Sources: Meat, fish, poultry, and dairy products.

Chromium - Helps in glucose metabolism.
Amount recommended: 0.05 to 0. 2 mg' is considered adequate and safe. Too much can be harmful.
Sources: Meat, dairy products, and whole-grains.

*See table for food equivalents.

Minerals in Selected Foods (1)

Food	Amount	Calcium (mg)	Phosphorous (mg)	Iron (mg)	Sodium (mg)	Magnesium (mg)	Zinc(2) (mg)
Meats, Poultry, Fish, and Beans Group
Beef	3 oz.	7	158	4.1	45	20	6.2
Chicken	3 oz.	14	200	1.5	78	18	1.2
Shrimp	3 oz.	63	166	1.6	140	42	2.1
Kidney beans	1/2 cup	38	140	2.4	3	70	1.0
Peanuts, unsalted	1 tablespoon	11	60	0.5	0.3	120	0.3
Milk and Cheese Group
Milk, whole	1 cup	298	234	0.1	127	31	1.0
Cheddar cheese	1 oz.	204	145	0.2	197	13	1.0
Breads and Cereals Group
Oatmeal	3/4 cup	153	169	13.5	135	25	0.1
Whole wheat bread	1 slice	23	52	0.5	121	18	0.6
Rice	3/4 cup	7	39	0.2	0.6	no data	0.1
Vegetables and Fruits Group
Turnip greens	1/2 cup	246	58	1.8	17	58	no data
Broccoli	1/2 cup	88	62	0.8	10	17	no data
Carrots	1/2 cup	33	31	0.6	33	25	0.3
Tomato, raw	1 medium	13	27	0.5	3	14	0.2
Cabbage, raw	1/2 cup	25	15	0.2	10	6	0.4
Orange juice	1/2 cup	15	21	0.2	1	14	0.07
Strawberries	10 whole	21	21	1.0	1	no data	no data
Fats and Sweets Group
Butter, salted	1 tablespoon	3	2	0	138	trace	trace
Corn oil	1 tablespoon	0	0	0	0	0	0
1 - From Bowes and Church, Food Values of Portions Commonly Used. 2 - From J. Am. Dietet. Assoc. 66:345, 1975.

References

Recommended Dietary Allowances, 9th ed.; National Academy of Science, Washington, D.C.; 1980.

Whitney, E., and Hamilton, M.; Understanding Nutrition; West Pub. Co., New York; 1977.