It is generally recommended that people eat a well-balanced diet to meet their mineral requirements, while avoiding deficiencies and chemical excesses or imbalances. However, supplements may be useful to meet dietary requirements for some minerals when dietary patterns fall short of Recommended Dietary Allowances (RDAs) or Adequate Intakes (AIs) for normal healthy people.
The Food and Nutrition Board currently recommends that supplements or fortified foods be used to obtain desirable amounts of some nutrients, such as calcium and iron. The recommendations for calcium are higher than the average intake in the United States. Women, who generally consume lower energy diets than men, and individuals who do not consume dairy products can particularly benefit from calcium supplements. Because of the increased need for iron in women of childbearing age, as well as the many negative consequences of iron-deficiency anemia, iron supplementation is recommended for vulnerable groups in the United States, as well as in developing countries.
Mineral supplementation may also be appropriate for people with prolonged illnesses or extensive injuries, for those undergoing surgery, or for those being treated for alcoholism. However, extra caution must be taken to avoid intakes greater than the RDA or AI for specific nutrients because of problems related to nutrient excesses, imbalances, or adverse interactions with medical treatments. Although toxic symptoms or adverse effects from excess supplementation have been reported for various minerals (e.g., calcium, magnesium, iron, zinc, copper, and selenium) and tolerable upper limits set, the amounts of nutrients in supplements are not regulated by the
The major minerals present in the body include sodium, potassium, chloride, calcium, magnesium, phosphorus, and sulfur.
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.
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Author Info: Sunitha Jasti, The Gale Group Inc., Macmillan Reference USA, New York, Gale Nutrition and Well-Being A to Z, 2004 |