Dietary mineral

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 chemical elements, not chemical compounds or actual minerals. Examples include calcium, magnesium, potassium, sodium, zinc, and iodine.

Dietitians may recommend that dietary elements are best supplied by ingesting specific foods rich with the chemical element(s) of interest. The elements may be naturally present in the food (e.g., calcium in dairy milk) or added to the food (e.g., orange juice fortified with calcium, salt fortified with iodine, iodized salt). Dietary supplements can provide several different chemical elements, a combination of vitamins and chemical elements, or a single elements, such as calcium or magnesium.

The dietary focus on chemical elements derives from an interest in supporting the biochemical reactions of metabolism with the required elemental components.[1] Appropriate intake levels of certain chemical elements are thus required to maintain optimal health. A healthful, balanced diet can meet all the body's chemical element requirements, although supplements can be used when some requirements (especially calcium, which is found mainly in dairy products) are not adequately met by the diet.

Contents

Essential chemical elements

Some sources state that sixteen chemical elements 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 elements are of relatively low atomic weight:

Periodic table highlighting dietary elements

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 element 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
Chlorine 2300 mg Quantity is needed for production of hydrochloric acid in the stomach and in cellular pump functions. Table salt (sodium chloride) is the main dietary source. 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 mass. 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 to prevent anemia. 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 not only for the synthesis of thyroid hormones, thyroxine and triiodothyronine and to prevent goiter, but also, probably as an antioxidant, for extrathyroidal organs as mammary and salivary glands and for gastric mucosa and immune system (thymus): iodine deficiency iodism
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

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]

Element Description Excess
Sulfur 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. (primarily associated with compounds)
Cobalt 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 dietary element deficiency. Cobalt poisoning
Nickel There have been occasional studies asserting the essentiality of nickel,[7] but it currently has no known RDA. Nickel toxicity
Chromium 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] Chromium toxicity
Fluorine Fluorine (as fluoride) has been described as conditionally essential, depending upon the importance placed upon the prevention of chronic disease.[11][12] Fluoride poisoning
Other 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. Multiple

See also

External links

References

  1. 1.0 1.1 Lippard, Stephen J.; Jeremy M. Berg (1994). Principles of Bioinorganic Chemistry. Mill Valley, CA: University Science Books. pp. 411. ISBN 0935702725. 
  2. 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. 
  3. 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. 
  4. "Linus Pauling Institute at Oregon State University". http://lpi.oregonstate.edu/infocenter/minerals/phosphorus/. Retrieved 2008-11-29. 
  5. Sardesai VM (December 1993). "Molybdenum: an essential trace element". Nutr Clin Pract 8 (6): 277–81. doi:10.1177/0115426593008006277. PMID 8302261. 
  6. "NSC 101 Chapter 8 Content". http://www.nutrition.arizona.edu/nsc101/chap08/ch08.htm. Retrieved 2008-12-02. 
  7. Anke M, Groppel B, Kronemann H, Grün M (1984). "Nickel--an essential element". IARC Sci. Publ. (53): 339–65. PMID 6398286. 
  8. "Linus Pauling Institute at Oregon State University". http://lpi.oregonstate.edu/infocenter/minerals/chromium/. Retrieved 2008-11-29. 
  9. 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:10.1080/10408440701845401. PMID 18324515. http://www.informaworld.com/openurl?genre=article&doi=10.1080/10408440701845401&magic=pubmed||1B69BA326FFE69C3F0A8F227DF8201D0. 
  10. Stearns DM (2000). "Is chromium a trace essential metal?". Biofactors 11 (3): 149–62. doi:10.1002/biof.5520110301. PMID 10875302. 
  11. Cerklewski FL (May 1998). "Fluoride--essential or just beneficial". Nutrition 14 (5): 475–6. doi:10.1016/S0899-9007(98)00023-9. PMID 9614319. http://linkinghub.elsevier.com/retrieve/pii/S0899900798000239. 
  12. "Linus Pauling Institute at Oregon State University". http://lpi.oregonstate.edu/infocenter/minerals/fluoride/. Retrieved 2008-11-29.