Summary Conclusions
A wide range of minerals is essential for human health. The recommended dietary allowances (RDAs) serve as guidelines for daily intakes of nutrients that population groups in the United States should have in their diets. Dietary Reference Intakes (DRIs) have been established for the following essential minerals: calcium, phosphorus, and magnesium. In addition, DRIs have been set for other trace elements, which have been identified to have important-if not essential roles in maintaining health. These include: iron, zinc, copper, manganese, selenium, boron, chromium, cobalt, molybdenum, vanadium, nickel, lithium, iodine and fluoride(1).
There is evidence that the need for mineral intake is not being met, especially in certain subpopulations. It is difficult for most individuals to ingest enough calcium from foods available in a cereal-based economy without liberal consumption of dairy products, for example.(2) Supplementation with minerals is recommended to complement dietary intake and avoid deficiencies. (3)
Mineral supplements are associated with different absorptive capacities. The absorption of minerals depends on a number of physiological, biochemical, and hormonal characteristics of the consumer and the form of the mineral consumed. Potential mineral sources are not all alike and should be evaluated for bioavailability.(4)
Factors that enhance mineral absorption include the form of the mineral ingested, maintenance of chemical stability, presence of a specific transporter, small particle size, solubility, ascorbic acid, and low intestinal motility. Factors that inhibit absorption include oxalic acid, phytic acid, (5) fiber(6), sodium, tannins(7), caffeine, protein, fat, antacids, rapid transit time, malabsorption syndromes, precipitation by alkalinization, other minerals(8), hormones and nutritional status(9).
Colloidal minerals exhibit properties that enhance absorption. Principles of biochemistry support the view that colloidal minerals may be more bioavailable than minerals in solid supplement or food forms.
A number of diseases are associated with mineral deficiencies or impaired metabolism of minerals. Supplementation with minerals has improved the nutritional status and lowered disease risk and progression factors among patients with arthritis, diabetes, cancer, anorexia, and hypertension.