Homespun
Homespun
January 31, 2001
Mining More of Your Body's Minerals
Last week, we learned about the major minerals in our bodies, their function and food sources. Today, we will take a look at the Trace Minerals. Known trace minerals include iodine, iron, fluoride, zinc, selenium, chromium, copper, manganese, cobalt, and molybdenum.
There are a number of elements that are suspected of being essential that suggest a beneficial role in human health: arsenic, boron, nickel, silicon, and vanadium. Scientists continue to study these elements, and have set and upper limit (UL) for toxicity for boron, nickel and vanadium.
While trace minerals are essential for life, they are extremely toxic when taken in large doses.
Iodine is part of thyroxin, a thyroid hormone that regulates the body's metabolic rate. The iodine of food reflects the soil it was grown in. The Great Plains region, for instance, has little iodine in the soil and goiters (enlargement of the thyroid gland) were once prevalent. Thanks to "iodized" salt, the goiter caused by iodine deficiency is very rare in the United States.
Iron is an important part of two oxygen-carrying molecules in the body, hemoglobin and myoglobin. Hemoglobin is the oxygen carrier in red blood cells, while myoglobin provides the oxygen reservoir for muscle cells. In iron-deficiency anemia, the red blood cells contain less hemoglobin and lose their ability to carry oxygen. A shortage of oxygen results in fatigue, apathy, pale skin, and the inability to concentrate. A simple blood test that measures the amount of hemoglobin the blood can detect iron-deficiency anemia. (There are also more complex tests that can detect iron depletion in the early stages.)
The best food sources or iron are lean meat, fish and poultry. They contain a form of iron know as heme iron, which is easily absorbed by the body. Non-heme sources of iron are found in soybeans, lima beans, almonds, peanut butter, dried apricots, raisins, spinach, potatoes, peas, winter squash and fortified cereals. Vitamin C enhances the absorption of non-heme iron. To get the most iron from plant-based foods, include a vitamin C source such as citrus, broccoli, kiwi, strawberries, peppers or potatoes with meals.
Fluoride is a mineral that plays an important role in the formation of teeth and bones. When fluoride intake is adequate, the crystalline deposits in bones and teeth are larger and more perfectly formed.
Zinc is an amazingly diverse mineral and is needed for healing wounds, normal taste perception, sperm formation, fetal development, and proper growth and sexual maturation. Zinc is needed to properly use vitamin A and helps the reactions of over 70 enzymes in the body. Present in whole grains and animal products, the RCA for zinc can be difficult to achieve. Zinc is extremely toxic in high doses.
Selenium is an antioxidant that works with vitamin E to protect body cells from oxidation and is also being studied for its possible role in cancer prevention. Selenium is widespread in foods and deficiency in the U. S. is rare.
The remaining trace minerals all play vital, if not always well understood, roles in the body. Chromium works with the hormone insulin to control blood sugar; copper is important for the formation of hemoglobin, connective tissue, nerve coverings and skin pigment. Cobalt is a component of vitamin B-12, and both manganese and molybdenum function as port of various enzymes in the body.
The best way to get all of the nutrients that you need is to eat a wide variety of foods in the amounts recommended the Food Guide Pyramid.
This page created by Margie Yarnell, Extension Secretary/Webmaster.
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