Homespun
Homespun
January 24, 2001
Mining Your Body's Minerals
Minerals are essential nutrients needed in small amounts. Minerals are classified as major or trace, based on the weight of the mineral present in the body. Each of the seven major minerals in the body weigh at least 5 grams (about a teaspoon), while trace minerals are present in amounts less than 5 grams.
The seven major minerals include calcium, phosphorus, sodium, chloride, potassium, magnesium and sulfur.
Calcium is best known for its contribution to the formation and maintenance of bone; 99% of the body's calcium is present in bones and teeth. Because the bones continually grow and develop throughout childhood and young adulthood, it is important to have adequate dietary calcium in these bone-formative years. It is believed that peak bone mass is reached at about age 24. After that, bones will not get much stronger and denser, but continued high calcium intake will help to maintain them.
The disease osteoporosis is characterized by mineral loss from the bones, resulting in porous, fragile bones that break easily. Although low calcium intake is a major risk factor for the disease, other factors also make individuals susceptible. Age, race, gender, family history, exercise habits, smoking, excesses of alcohol, protein, caffeine and fiber, and a lack of calcium and vitamin D all contribute to adult bone loss. Elderly white women are the group at the highest risk for osteoporosis. It is important to prevent this disease by stressing positive, life-long nutrition and health habits, especially for women.
The remaining 1% of the body's calcium is present in the blood and body fluids. Calcium plays vital roles in nerve transmission, muscle contractions, blood clotting, maintenance of normal blood pressure and as part of the "glue" that holds the cells together.
Food sources of calcium include milk and dairy products, fish with bones (ie, canned sardines and salmon), dark green vegetables such as broccoli and kale, and calcium-fortified foods and beverages.
Phosphorus (85%) is combined with calcium in the bones and teeth. The remaining 15% aids the cells in the use of energy nutrients, and is part of the genetic material. Phosphorus is widespread in the food supply so deficiency is rare. Dietary excess is common due to the high phosphorus content of soft drinks (particularly cola beverages).
Sodium regulates the fluid balance inside and outside of the body's cells. Since sodium particles attract water, too much sodium can cause fluid retention. Sodium can also aggravate hypertension (high blood pressure) in susceptible people. A common recommendation for those diagnosed with hypertension is to reduce the amount of dietary sodium. (Obesity and alcohol also worsen hypertension. There is also evidence that potassium calcium and magnesium protect against high blood pressure. Thus, a balanced diet with plenty of fruits, vegetables and dairy is important in the management of high blood pressure.)
A deficiency of dietary sodium is rare, since high amounts of this mineral pervade the food supply. Instead, health experts worry about excesses of sodium. Many experts recommend an upper limit of 2400 milligrams of sodium per day.
Salt (chemical name: sodium chloride) is 40% sodium. A teaspoon of salt provides about 2000 milligrams of sodium. But even without the salt shaker, most people greatly exceed 2400 milligrams each day due to the widespread use of salt and other sodium compounds in the food supply. Careful label reading is important to compare the sodium content of foods.
Chloride functions as part of the acid in the stomach (hydrochloric acid). The major source is table salt. Dietary deficiency is rare.
Potassium is a critical element, responsible for maintaining the heartbeat, regulating fluid balance, and is important for proper nerve transmission and muscle contractions.
Potassium is lost in sweat, so heavy exercisers need to replace it through food or drink. Certain diuretics also cause potassium loss from the body. Fruits and vegetables are the best food sources of potassium, especially bananas, tomatoes, potatoes, oranges, and sports drinks.
Like calcium and phosphorus, most of the body's magnesium is present in the bones. The small amount present in the rest of the body is needed for the release of energy from the energy nutrients, and relaxation of muscle fibers following contractions and the conduction of nerve impulses. Deficiency is most commonly seen in chronic alcoholism, where dietary habits and absorption of nutrients tend to be poor. Food sources include nuts, legumes, cereals, dark green vegetables, seafood, and chocolate.
Sulfur is present in all body and dietary proteins. There is no RDA for sulfur, since a diet adequate in protein will also contain ample sulfur.
Next week we will continue with the trace minerals.
This page created by Margie Yarnell, Extension Secretary/Webmaster.
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