Minerals Health Article

Functions.

Trace minerals have specific biological functions. They are essential in the absorption and utilization of many nutrients and aid enzymes and hormones in activities that are vital to life. Iron plays a major role in oxygen transport and storage and is a component of hemoglobin in red blood cells and myoglobin in muscle cells. Cellular energy production requires many trace minerals, including iron, copper, and zinc, which act as enzyme cofactors in the synthesis of many proteins, hormones, neurotransmitters, and genetic material.

Iron and zinc support immune function, while chromium and zinc aid insulin action. Zinc is also essential for many other bodily functions, such as growth, development of sexual organs, and reproduction. Zinc, copper and selenium prevent oxidative damage to cells. Fluoride stabilizes bone mineral and hardens tooth enamel, thus increasing resistance to tooth decay. Iodine is essential for normal thyroid function, which is critical for many aspects of growth and development, particularly brain development. Thus, trace minerals contribute to physical growth and mental development.

Disease prevention and treatment.

Sodium, chloride, and potassium are linked to high blood pressure (hypertension) due to their role in the body's fluid balance. High salt or sodium chloride intake has been linked to cardiovascular disease as well. High potassium intakes, on the other hand, have been associated with a lower risk of stroke, particularly in people with hypertension. Research also suggests a preventive role for magnesium in hypertension and cardiovascular disease, as well as a beneficial effect in the treatment of diabetes, osteoporosis, and migraine headaches.

Osteoporosis is a bone disorder in which bone strength is compromised, leading to an increased risk of fracture. Along with other lifestyle factors, intake of calcium and vitamin D plays an important role in the maintenance of bone health and the prevention and treatment of osteoporosis. Good calcium nutrition, along with low salt and high potassium intake, has been linked to prevention of hypertension and kidney stones.

Deficiency.

With the exception of iron, dietary deficiencies are rare in the United States and other developed nations. However, malnutrition in developing countries increases the risk for trace-mineral deficiencies among children and other vulnerable groups. In overzealous supplement users, interactions among nutrients can inhibit absorption of some minerals leading to deficiencies. Patients on intravenous feedings without mineral supplements are at risk of developing deficiencies as well.

Although severe deficiencies of better-understood trace minerals are easy to recognize, diagnosis is difficult for less-understood minerals and for mild deficiencies. Even mild deficiencies of trace minerals however, can result in poor growth and development in children.

Iron deficiency is the most common nutrient deficiency worldwide, including in the United States. Iron-deficiency anemia affects hundreds of millions of people, with highest prevalence in developing countries. Infants, young children, adolescents, and pregnant and lactating women are especially vulnerable due to their high demand for iron. Menstruating women are also vulnerable due to blood loss. Vegetarians are another vulnerable group, as iron from plant foods is less bioavailable than that from animal sources.

Zinc deficiency, marked by severe growth retardation and arrested sexual development, was first reported in children and adolescent boys in Egypt, Iran, and Turkey. Diets in Middle Eastern countries are typically high in fiber and phytates, which inhibit zinc absorption. Mild zinc deficiency has been found in vulnerable groups in the United States. Copper deficiency is rare, but can be caused by excess zinc from supplementation.

Deficiencies of fluoride, iodine, and selenium mainly occur due to a low mineral content in either the water or soil in some areas of the world. Fluoride deficiency is marked by a high prevalence of dental caries and is common in geographic regions with low water-fluoride concentration, which has led to the fluoridation of water in the United States and many other parts of the world. Goiter and cretinism (a condition in which body growth and mental development are stunted) have been eliminated by iodization of salt in the United States, but still occur in parts of the world where salt manufacture and distribution are not regulated. Selenium deficiency due to low levels of the mineral in soil is found in northeast China, and it has been associated with Keshan disease, a heart disorder prevalent among people of that area.