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 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.
Dietitians may recommend that dietary minerals are best supplied by ingesting specific foods rich with the element(s) of interest. Sometimes dietary minerals are ingested as part of dietary supplements, the most common being iodine in iodized salt.
The dietary focus on dietary minerals derives from an interest in supporting biochemical reactions with the required elemental components.[1] Appropriate intake levels of certain chemical elements are thus required to maintain optimal health. According to nutritional experts, the requirements are met simply with a conventional balanced diet.[citation needed]
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[edit] Essential dietary minerals
Some sources state that sixteen dietary minerals are required to support human biochemical processes by serving structural and functional roles as well as electrolytes:[2] Sometimes a distinction is drawn between this category and micronutrients. Most of the dietary minerals are of relatively low atomic weight:
Periodic table highlighting dietary minerals
| H | He | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Li | Be | B | C | N | O | F | Ne | |||||||||||
| Na | Mg | Al | Si | P | S | Cl | Ar | |||||||||||
| K | Ca | Sc | Ti | V | Cr | Mn | Fe | Co | Ni | Cu | Zn | Ga | Ge | As | Se | Br | Kr | |
| Rb | Sr | Y | Zr | Nb | Mo | Tc | Ru | Rh | Pd | Ag | Cd | In | Sn | Sb | Te | I | Xe | |
| Cs | Ba | La | * | Hf | Ta | W | Re | Os | Ir | Pt | Au | Hg | Tl | Pb | Bi | Po | At | Rn |
| Fr | Ra | Ac | ** | Rf | Db | Sg | Bh | Hs | Mt | Ds | Rg | |||||||
| * | Ce | Pr | Nd | Pm | Sm | Eu | Gd | Tb | Dy | Ho | Er | Tm | Yb | Lu | ||||
| ** | Th | Pa | U | Np | Pu | Am | Cm | Bk | Cf | Es | Fm | Md | No | Lr | ||||
| The four organic basic elements | Quantity elements | Essential trace elements | Pervasive but no identified biological function in humans |
The following play important roles in biological processes:
| Dietary mineral | RDA/AI | Description | Category | Insufficiency | Excess | |
|---|---|---|---|---|---|---|
| Potassium | 4700 mg | Quantity | is a systemic electrolyte and is essential in coregulating ATP with sodium. Dietary sources include legumes, potato skin, tomatoes, and bananas. | hypokalemia | hyperkalemia | |
| Chloride | 2300 mg | Quantity | is needed for production of hydrochloric acid in the stomach and in cellular pump functions. Table salt is the main dietary source of chloride. | hypochloremia | hyperchloremia | |
| Sodium | 1500 mg | Quantity | is a systemic electrolyte and is essential in coregulating ATP with potassium. Dietary sources include table salt (sodium chloride, the main source), sea vegetables, milk, and spinach. | hyponatremia | hypernatremia | |
| Calcium | 1000 mg | Quantity | is needed for muscle, heart and digestive system health, builds bone, supports synthesis and function of blood cells. Dietary sources of calcium include dairy products, canned fish with bones (salmon, sardines), green leafy vegetables, nuts and seeds. | hypocalcaemia | hypercalcaemia | |
| Phosphorus | 700 mg | Quantity | is a component of bones (see apatite) and energy processing and many other functions.[3] In biological contexts, usually seen as phosphate.[4] | hypophosphatemia | hyperphosphatemia | |
| Magnesium | 420 mg | Quantity | is required for processing ATP and for bones. Dietary sources include nuts, soy beans, and cocoa. | hypomagnesemia, magnesium deficiency |
hypermagnesemia | |
| Zinc | 11 mg | Trace | is pervasive and required for several enzymes such as carboxypeptidase, liver alcohol dehydrogenase, and carbonic anhydrase. | zinc deficiency | zinc toxicity | |
| Iron | 8 mg | Trace | is required for many proteins and enzymes, notably hemoglobin. Dietary sources include red meat, leafy green vegetables, fish (tuna, salmon), eggs, dried fruits, beans, whole grains, and enriched grains. | anaemia | iron overload disorder | |
| Manganese | 2.3 mg | Trace | is a cofactor in enzyme functions. | manganese deficiency | manganism | |
| Copper | 900 µg | Trace | is required component of many redox enzymes, including cytochrome c oxidase. | copper deficiency | copper toxicity | |
| Iodine | 150 µg | Trace | is required for the biosynthesis of thyroxine. | iodine deficiency | ||
| Selenium | 55 µg | Trace | a cofactor essential to activity of antioxidant enzymes like glutathione peroxidase. | selenium deficiency | selenosis | |
| Molybdenum | 45 µg | Trace | the oxidases xanthine oxidase, aldehyde oxidase, and sulfite oxidase[5] | molybdenum deficiency |
[edit] Other elements
Many elements have been suggested as essential, but such claims have usually not been confirmed. Definitive evidence for efficacy comes from the characterization of a biomolecule containing the element with an identifiable and testable function. One problem with identifying efficacy is that some elements are innocuous at low concentrations and are pervasive, so proof of efficacy is lacking because deficiencies are difficult to reproduce.[1]
- Relatively large quantities of sulfur are required, but there is no RDA,[6] as the sulfur is obtained from and used for amino acids, and therefore should be adequate in any diet containing enough protein.
- Cobalt is required in the synthesis of vitamin B12, but because bacteria are required to synthesize the vitamin, it is usually considered part of vitamin B12 deficiency rather than its own mineral deficiency.
- There have been occasional studies asserting the essentiality of nickel,[7] but it currently has no known RDA.
- Chromium is sometimes described as essential.[8][9] It is implicated in sugar metabolism in humans, leading to a market for the supplement, chromium picolinate, but definitive biochemical evidence for a physiological function is lacking.[10]
- Fluoride has been described as conditionally essential, depending upon the importance placed upon the prevention of chronic disease.[11][12]
- Arsenic, boron, bromine, cadmium, silicon, tungsten, and vanadium have established, albeit specialized, biochemical roles as structural or functional cofactors in other organisms. These elements appear not to be utilized by humans.[citation needed]
[edit] See also
[edit] External links
[edit] References
- ^ a b Lippard, Stephen J.; Jeremy M. Berg (1994). Principles of Bioinorganic Chemistry. Mill Valley, CA: University Science Books. pp. 411. ISBN 0935702725.
- ^ Nelson, David L.; Michael M. Cox (2000-02-15). Lehninger Principles of Biochemistry, Third Edition (3 Har/Com ed.). W. H. Freeman. pp. 1200. ISBN 1572599316.
- ^ Corbridge, D. E. C. (1995-02-01). Phosphorus: An Outline of Its Chemistry, Biochemistry, and Technology (5th ed.). Amsterdam: Elsevier Science Pub Co. pp. 1220. ISBN 0444893075.
- ^ "Linus Pauling Institute at Oregon State University". http://lpi.oregonstate.edu/infocenter/minerals/phosphorus/. Retrieved 2008-11-29.
- ^ Sardesai VM (December 1993). "Molybdenum: an essential trace element". Nutr Clin Pract 8 (6): 277–81. doi:. PMID 8302261.
- ^ "NSC 101 Chapter 8 Content". http://www.nutrition.arizona.edu/nsc101/chap08/ch08.htm. Retrieved 2008-12-02.
- ^ Anke M, Groppel B, Kronemann H, Grün M (1984). "Nickel--an essential element". IARC Sci. Publ. (53): 339–65. PMID 6398286.
- ^ "Linus Pauling Institute at Oregon State University". http://lpi.oregonstate.edu/infocenter/minerals/chromium/. Retrieved 2008-11-29.
- ^ Eastmond DA, Macgregor JT, Slesinski RS (2008). "Trivalent chromium: assessing the genotoxic risk of an essential trace element and widely used human and animal nutritional supplement". Crit. Rev. Toxicol. 38 (3): 173–90. doi:. PMID 18324515. http://www.informaworld.com/openurl?genre=article&doi=10.1080/10408440701845401&magic=pubmed||1B69BA326FFE69C3F0A8F227DF8201D0.
- ^ Stearns DM (2000). "Is chromium a trace essential metal?". Biofactors 11 (3): 149–62. doi:. PMID 10875302.
- ^ Cerklewski FL (May 1998). "Fluoride--essential or just beneficial". Nutrition 14 (5): 475–6. PMID 9614319. http://linkinghub.elsevier.com/retrieve/pii/S0899900798000239.
- ^ "Linus Pauling Institute at Oregon State University". http://lpi.oregonstate.edu/infocenter/minerals/fluoride/. Retrieved 2008-11-29.
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