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Dietary mineral



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Dietary minerals are the chemical elements required by living organisms, other than the four elements carbon, hydrogen, nitrogen, and oxygen which are present in common organic molecules. The term "mineral" is archaic, since the intent of the definition is to describe ions, not chemical compounds or actual minerals. Furthermore, once dissolved, so-called minerals do not exist as such, sodium chloride breaks down into sodium ions and chloride ions in aqueous solution. Some dietitians recommend that these heavier elements should be supplied by ingesting specific foods (that are enriched in the element(s) of interest), compounds, and sometimes including even minerals, such as calcium carbonate. Sometimes these "minerals" come from natural sources such as ground oyster shells. Sometimes minerals are added to the diet separately from food, such as mineral supplements, the most famous being iodine in "iodized salt." Dirt eating, called pica or geophagy is practiced by some as a means of supplementing the diet with elements. The chemical composition of soils will vary depending on the location.

Vitamins, which are not considered minerals, are organic compounds, some of which contain heavy elements such as iodine and cobalt. The dietary focus on "minerals" derives from an interest in supporting the biosynthetic apparatus with the required elemental components.[1] Appropriate intake levels of certain chemical elements is thus required to maintain optimal health. Commonly, the requirements are met with a conventional diet. Excessive intake of any element (again, usually as an ion) will lead to poisoning. For example, large doses of selenium are lethal. On the other hand, large doses of zinc are less dangerous but can lead to a harmful copper deficiency (unless compensated for, as in the Age-Related Eye Disease Study).

Dietary minerals classified as "macromineral" are required in relatively large amounts. Conversely "microminerals" or "trace minerals" are required relatively in minute amounts. There is no universally accepted definition of the difference between "large" and "small" amounts.

 

Additional recommended knowledge

Contents

Macrominerals

A variety of elements are required to support the biochemical processes, many play a role as electrolytes or in a structural role.[2] In Human nutrition, the dietary bulk "mineral elements" (RDA > 200 mg/day) are in alphabetical order (parenthetical comments on folk medicine perspective):

  • Calcium (for muscle and digestive system health, builds bone, neutralizes acidity, clears toxins, helps blood stream)
  • Chloride (for production of hydrochloric acid in the stomach)
  • Magnesium is required for processing ATP and related reactions (health, builds bone, causes strong peristalsis, increases flexibility, increases alkalinity)
  • Phosphorus is a component of bones (see apatite) and energy processing and many other functions (bone mineralization)[3]
  • Potassium is an electrolyte (heart and nerves health)
  • Sodium is an electrolyte
  • Sulfur is an essential element for life in cysteine and methionine amino acids and some cofactors

Trace minerals

A variety of elements are required in trace amounts, unusually because they play a role in catalysis in enzymes.[1] Some trace mineral elements (RDA < 200 mg/day) are (alphabetical order):[citation needed]

  • Cobalt is required for biosynthesis of vitamin B12 family of coenzymes
  • Copper is required component of many redox enzymes, including cytochrome c oxidase
  • Fluorine for tooth enamel which contains fluoroapatite (see Water fluoridation controversy)
  • Iodine is required for the biosynthesis of thyroxin, is required in larger quantities than the other trace minerals in this list and is sometimes classified with the bulk minerals
  • Iron is required for many proteins and enzymes, notably hemoglobin
  • Manganese (processing of oxygen)
  • Molybdenum is required for xanthine oxidase and related oxidases
  • Nickel present in urease
  • Selenium is required for peroxidase (antioxidant proteins)
  • Vanadium (There is no established RDA for vanadium. No specific biochemical function has been identified for it in humans, although vanadium is found in lower organisms)
  • Zinc is pervasive and required for several enzymes such as carboxypeptidase, liver alcohol dehydrogenase, carbonic anhydrase

Other trace minerals

Many elements have been suggested as required in human nutrition, but such claims are often suspect as pseudoscience. One problem with identifying efficacyis arises because many elements are innocuous at low concentrations, so proof of efficacy is lacking. Definitive evidence for efficacy comes from characterization of a biomolecule with an identifiable and testable function. Of the many ultratrace elements still lacking solid proof, chromium is often cited. Chromium(III) is implicated in sugar metabolism in humans, leading to a market for chromium picolinate.


Food sources

  • Dairy products, calcium-fortified foods, canned fish with bones (salmon, sardines), and green leafy vegetables for calcium
  • Nuts, soy beans, and cocoa for magnesium
  • Table salt (sodium chloride, the main source), sea vegetables, olives, milk, and spinach for sodium
  • Legumes, potato skin, tomatoes, and bananas for potassium
  • Table salt is the main dietary source for chlorine
  • Meat, eggs, and legumes for sulfur
  • Red meat, leafy green vegetables, fish (tuna, salmon), eggs, dried fruits, beans, whole grains, and enriched grains for iron

See also

References

  1. ^ a b Lippard, Stephen J.; Jeremy M. Berg (1994). Principles of Bioinorganic Chemistry. Mill Valley, CA: University Science Books, 411. ISBN 0935702725. 
  2. ^ Nelson, David L.; Michael M. Cox (2000-02-15). Lehninger Principles of Biochemistry, Third Edition, 3 Har/Com, W. H. Freeman, 1200. ISBN 1572599316. 
  3. ^ Corbridge, D. E. C. (1995-02-01). Phosphorus: An Outline of Its Chemistry, Biochemistry, and Technology, 5th, Amsterdam: Elsevier Science Pub Co, 1220. ISBN 0444893075. 
  • Donatelle, Rebecca J. (2004-03-29). Health: The Basics, 6th edition, San Frnacisco: Benjamin Cummings, 480. ISBN 0805328521. 
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Dietary_mineral". A list of authors is available in Wikipedia.
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