Essential nutrient
Encyclopedia
An essential nutrient is a nutrient
required for normal body functioning that either cannot be synthesized by the body at all, or cannot be synthesized in amounts adequate for good health (e.g. niacin
, choline
), and thus must be obtained from a dietary
source. Essential nutrients are also defined by the collective physiological evidence for their importance in the diet, as represented in e.g. US government approved tables for Dietary Reference Intake
.
Some categories of essential nutrients include vitamin
s, dietary minerals, essential fatty acid
s, and essential amino acid
s. Water
and oxygen
are also essential for human health and life, as oxygen cannot be synthesized by the body, and water, while a biochemical reaction product of metabolism, is not created in sufficient amounts. Both are necessary as biochemical reactants in some processes, and water is used in various ways such as a solvent, carrier, and coolant, but neither is considered to be a nutrient.
Different species have very different essential nutrients. For example, most mammals synthesize their own ascorbic acid
, and it is therefore not considered an essential nutrient for such species. It is, however, an essential nutrient for human beings, who require external sources of ascorbic acid (known as Vitamin C in the context of nutrition).
Many essential nutrients are toxic in large doses (see hypervitaminosis or the nutrient pages themselves below). Some can be taken in amounts larger than required in a typical diet, with no apparent ill effects. Linus Pauling
said of vitamin B3
, (either niacin or niacinamide), "What astonished me was the very low toxicity of a substance that has such very great physiological power. A little pinch, 5 mg, every day, is enough to keep a person from dying of pellagra
, but it is so lacking in toxicity that ten thousand times as much can [sometimes] be taken without harm." However, large quantities of some vitamins are life-threatening (e.g. excessive amounts of Vitamin D, a fat-soluble nutrient involved in maintaining adequate blood-calcium levels, can lead to nausea, vomiting, stupor, and death via cardiac arrhythmia and arrest).
The required quantity varies widely between nutrients. At one extreme, a 70 kg human contains 1.0 kg of calcium, but only 3 mg of cobalt.
been established:
Nutrient
A nutrient is a chemical that an organism needs to live and grow or a substance used in an organism's metabolism which must be taken in from its environment. They are used to build and repair tissues, regulate body processes and are converted to and used as energy...
required for normal body functioning that either cannot be synthesized by the body at all, or cannot be synthesized in amounts adequate for good health (e.g. niacin
Niacin
"Niacin" redirects here. For the neo-fusion band, see Niacin .Niacin is an organic compound with the formula and, depending on the definition used, one of the forty to eighty essential human nutrients.Niacin is one of five vitamins associated with a pandemic deficiency disease: niacin deficiency...
, choline
Choline
Choline is a water-soluble essential nutrient. It is usually grouped within the B-complex vitamins. Choline generally refers to the various quaternary ammonium salts containing the N,N,N-trimethylethanolammonium cation....
), and thus must be obtained from a dietary
Diet (nutrition)
In nutrition, diet is the sum of food consumed by a person or other organism. Dietary habits are the habitual decisions an individual or culture makes when choosing what foods to eat. With the word diet, it is often implied the use of specific intake of nutrition for health or weight-management...
source. Essential nutrients are also defined by the collective physiological evidence for their importance in the diet, as represented in e.g. US government approved tables for Dietary Reference Intake
Dietary Reference Intake
The Dietary Reference Intake is a system of nutrition recommendations from the Institute of Medicine of the U.S. National Academy of Sciences. The DRI system is used by both the United States and Canada and is intended for the general public and health professionals...
.
Some categories of essential nutrients include vitamin
Vitamin
A vitamin is an organic compound required as a nutrient in tiny amounts by an organism. In other words, an organic chemical compound is called a vitamin when it cannot be synthesized in sufficient quantities by an organism, and must be obtained from the diet. Thus, the term is conditional both on...
s, dietary minerals, essential fatty acid
Essential fatty acid
Essential fatty acids, or EFAs, are fatty acids that humans and other animals must ingest because the body requires them for good health but cannot synthesize them...
s, and essential amino acid
Essential amino acid
An essential amino acid or indispensable amino acid is an amino acid that cannot be synthesized de novo by the organism , and therefore must be supplied in the diet.-Essentiality vs. conditional essentiality in humans:...
s. Water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
and oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
are also essential for human health and life, as oxygen cannot be synthesized by the body, and water, while a biochemical reaction product of metabolism, is not created in sufficient amounts. Both are necessary as biochemical reactants in some processes, and water is used in various ways such as a solvent, carrier, and coolant, but neither is considered to be a nutrient.
Different species have very different essential nutrients. For example, most mammals synthesize their own ascorbic acid
Ascorbic acid
Ascorbic acid is a naturally occurring organic compound with antioxidant properties. It is a white solid, but impure samples can appear yellowish. It dissolves well in water to give mildly acidic solutions. Ascorbic acid is one form of vitamin C. The name is derived from a- and scorbutus , the...
, and it is therefore not considered an essential nutrient for such species. It is, however, an essential nutrient for human beings, who require external sources of ascorbic acid (known as Vitamin C in the context of nutrition).
Many essential nutrients are toxic in large doses (see hypervitaminosis or the nutrient pages themselves below). Some can be taken in amounts larger than required in a typical diet, with no apparent ill effects. Linus Pauling
Linus Pauling
Linus Carl Pauling was an American chemist, biochemist, peace activist, author, and educator. He was one of the most influential chemists in history and ranks among the most important scientists of the 20th century...
said of vitamin B3
Niacin
"Niacin" redirects here. For the neo-fusion band, see Niacin .Niacin is an organic compound with the formula and, depending on the definition used, one of the forty to eighty essential human nutrients.Niacin is one of five vitamins associated with a pandemic deficiency disease: niacin deficiency...
, (either niacin or niacinamide), "What astonished me was the very low toxicity of a substance that has such very great physiological power. A little pinch, 5 mg, every day, is enough to keep a person from dying of pellagra
Pellagra
Pellagra is a vitamin deficiency disease most commonly caused by a chronic lack of niacin in the diet. It can be caused by decreased intake of niacin or tryptophan, and possibly by excessive intake of leucine. It may also result from alterations in protein metabolism in disorders such as carcinoid...
, but it is so lacking in toxicity that ten thousand times as much can [sometimes] be taken without harm." However, large quantities of some vitamins are life-threatening (e.g. excessive amounts of Vitamin D, a fat-soluble nutrient involved in maintaining adequate blood-calcium levels, can lead to nausea, vomiting, stupor, and death via cardiac arrhythmia and arrest).
Fatty acids
- α-Linolenic acidAlpha-linolenic acidα-Linolenic acid is an organic compound found in many common vegetable oils. In terms of its structure, it is named all-cis-9,12,15-octadecatrienoic acid. In physiological literature, it is given the name 18:3 ....
(the shortest chain omega-3 fatty acidOmega-3 fatty acidN−3 fatty acids are essential unsaturated fatty acids with a double bond starting after the third carbon atom from the end of the carbon chain....
) - Linoleic acidLinoleic acidLinoleic acid is an unsaturated n-6 fatty acid. It is a colorless liquid at room temperature. In physiological literature, it has a lipid number of 18:2...
(the shortest chain omega-6 fatty acid)
Amino acids
- IsoleucineIsoleucineIsoleucine is an α-amino acid with the chemical formula HO2CCHCHCH2CH3. It is an essential amino acid, which means that humans cannot synthesize it, so it must be ingested. Its codons are AUU, AUC and AUA....
- LysineLysineLysine is an α-amino acid with the chemical formula HO2CCH4NH2. It is an essential amino acid, which means that the human body cannot synthesize it. Its codons are AAA and AAG....
- LeucineLeucineLeucine is a branched-chain α-amino acid with the chemical formula HO2CCHCH2CH2. Leucine is classified as a hydrophobic amino acid due to its aliphatic isobutyl side chain. It is encoded by six codons and is a major component of the subunits in ferritin, astacin and other 'buffer' proteins...
- MethionineMethionineMethionine is an α-amino acid with the chemical formula HO2CCHCH2CH2SCH3. This essential amino acid is classified as nonpolar. This amino-acid is coded by the codon AUG, also known as the initiation codon, since it indicates mRNA's coding region where translation into protein...
- PhenylalaninePhenylalaninePhenylalanine is an α-amino acid with the formula C6H5CH2CHCOOH. This essential amino acid is classified as nonpolar because of the hydrophobic nature of the benzyl side chain. L-Phenylalanine is an electrically neutral amino acid, one of the twenty common amino acids used to biochemically form...
- ThreonineThreonineThreonine is an α-amino acid with the chemical formula HO2CCHCHCH3. Its codons are ACU, ACA, ACC, and ACG. This essential amino acid is classified as polar...
- TryptophanTryptophanTryptophan is one of the 20 standard amino acids, as well as an essential amino acid in the human diet. It is encoded in the standard genetic code as the codon UGG...
- ValineValineValine is an α-amino acid with the chemical formula HO2CCHCH2. L-Valine is one of 20 proteinogenic amino acids. Its codons are GUU, GUC, GUA, and GUG. This essential amino acid is classified as nonpolar...
- HistidineHistidineHistidine Histidine, an essential amino acid, has a positively charged imidazole functional group. It is one of the 22 proteinogenic amino acids. Its codons are CAU and CAC. Histidine was first isolated by German physician Albrecht Kossel in 1896. Histidine is an essential amino acid in humans...
- Essential amino acids necessary for preterm children but not healthy individuals:
- ArginineArginineArginine is an α-amino acid. The L-form is one of the 20 most common natural amino acids. At the level of molecular genetics, in the structure of the messenger ribonucleic acid mRNA, CGU, CGC, CGA, CGG, AGA, and AGG, are the triplets of nucleotide bases or codons that codify for arginine during...
- Arginine
Vitamins
- Vitamin AVitamin AVitamin A is a vitamin that is needed by the retina of the eye in the form of a specific metabolite, the light-absorbing molecule retinal, that is necessary for both low-light and color vision...
(retinol) - Vitamin BpCholineCholine is a water-soluble essential nutrient. It is usually grouped within the B-complex vitamins. Choline generally refers to the various quaternary ammonium salts containing the N,N,N-trimethylethanolammonium cation....
(cholineCholineCholine is a water-soluble essential nutrient. It is usually grouped within the B-complex vitamins. Choline generally refers to the various quaternary ammonium salts containing the N,N,N-trimethylethanolammonium cation....
) - Vitamin B1 (thiamin)
- Vitamin B2 (riboflavin, vitamin G)
- Vitamin B3 (niacin, vitamin P, vitamin PP)
- Vitamin B5 (pantothenic acid)
- Vitamin B6Vitamin B6Vitamin B6 is a water-soluble vitamin and is part of the vitamin B complex group. Several forms of the vitamin are known, but pyridoxal phosphate is the active form and is a cofactor in many reactions of amino acid metabolism, including transamination, deamination, and decarboxylation...
(pyridoxinePyridoxinePyridoxine is one of the compounds that can be called vitamin B6, along with pyridoxal and pyridoxamine. It differs from pyridoxamine by the substituent at the '4' position. It is often used as 'pyridoxine hydrochloride'.-Chemistry:...
, pyridoxaminePyridoxaminePyridoxamine is a vitamer in the vitamin B6 family, which includes pyridoxal and pyridoxine. Pyridoxamine is converted to the biologically active form of vitamin B6, pyridoxal 5-phosphate, via the vitamin B6 salvage pathway. Vitamin B6 acts as an enzyme cofactor in a variety of metabolic processes...
, or pyridoxalPyridoxalPyridoxal is one of the three natural forms of vitamin B6, along with pyridoxamine and pyridoxine . All of these forms are converted in the human body into a single biologically active form, pyridoxal 5-phosphate. All three forms of vitamin B6 are heterocyclic organic compounds...
) - Vitamin B7 (biotin, vitamin H)
- Vitamin B9 (folic acid, folate, vitamin M)
- Vitamin B12Vitamin B12Vitamin B12, vitamin B12 or vitamin B-12, also called cobalamin, is a water-soluble vitamin with a key role in the normal functioning of the brain and nervous system, and for the formation of blood. It is one of the eight B vitamins...
(cobalamin) - Vitamin CVitamin CVitamin C or L-ascorbic acid or L-ascorbate is an essential nutrient for humans and certain other animal species. In living organisms ascorbate acts as an antioxidant by protecting the body against oxidative stress...
(ascorbic acidAscorbic acidAscorbic acid is a naturally occurring organic compound with antioxidant properties. It is a white solid, but impure samples can appear yellowish. It dissolves well in water to give mildly acidic solutions. Ascorbic acid is one form of vitamin C. The name is derived from a- and scorbutus , the...
) - Vitamin DVitamin DVitamin D is a group of fat-soluble secosteroids. In humans, vitamin D is unique both because it functions as a prohormone and because the body can synthesize it when sun exposure is adequate ....
(ergocalciferolErgocalciferolErgocalciferol is a form of vitamin D, also called vitamin D2. It is marketed under various names including Deltalin , Drisdol and Calcidol...
, or cholecalciferolCholecalciferolCholecalciferol is a form of vitamin D, also called vitamin D3 or calciol.It is structurally similar to steroids such as testosterone, cholesterol, and cortisol .-Forms:Vitamin D3 has several forms:...
) - Vitamin EVitamin EVitamin E is used to refer to a group of fat-soluble compounds that include both tocopherols and tocotrienols. There are many different forms of vitamin E, of which γ-tocopherol is the most common in the North American diet. γ-Tocopherol can be found in corn oil, soybean oil, margarine and dressings...
(tocopherol) - Vitamin KVitamin KVitamin K is a group of structurally similar, fat soluble vitamins that are needed for the posttranslational modification of certain proteins required for blood coagulation and in metabolic pathways in bone and other tissue. They are 2-methyl-1,4-naphthoquinone derivatives...
(naphthoquinoids)
Dietary minerals
- CalciumCalciumCalcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
(Ca) - ChlorideChlorideThe chloride ion is formed when the element chlorine, a halogen, picks up one electron to form an anion Cl−. The salts of hydrochloric acid HCl contain chloride ions and can also be called chlorides. The chloride ion, and its salts such as sodium chloride, are very soluble in water...
(Cl−) - ChromiumChromiumChromium is a chemical element which has the symbol Cr and atomic number 24. It is the first element in Group 6. It is a steely-gray, lustrous, hard metal that takes a high polish and has a high melting point. It is also odorless, tasteless, and malleable...
(Cr) - CobaltCobaltCobalt is a chemical element with symbol Co and atomic number 27. It is found naturally only in chemically combined form. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal....
(Co) (as part of Vitamin B-12) - CopperCopperCopper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
(Cu) - IodineIodineIodine is a chemical element with the symbol I and atomic number 53. The name is pronounced , , or . The name is from the , meaning violet or purple, due to the color of elemental iodine vapor....
(I) - IronIronIron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
(Fe) - MagnesiumMagnesiumMagnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...
(Mg) - ManganeseManganeseManganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a free element in nature , and in many minerals...
(Mn) - MolybdenumMolybdenumMolybdenum , is a Group 6 chemical element with the symbol Mo and atomic number 42. The name is from Neo-Latin Molybdaenum, from Ancient Greek , meaning lead, itself proposed as a loanword from Anatolian Luvian and Lydian languages, since its ores were confused with lead ores...
(Mo) - NickelNickelNickel is a chemical element with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile...
(Ni) - PhosphorusPhosphorusPhosphorus is the chemical element that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus as a mineral is almost always present in its maximally oxidized state, as inorganic phosphate rocks...
(P) - PotassiumPotassiumPotassium is the chemical element with the symbol K and atomic number 19. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.Potassium and sodium are...
(K) - SeleniumSeleniumSelenium is a chemical element with atomic number 34, chemical symbol Se, and an atomic mass of 78.96. It is a nonmetal, whose properties are intermediate between those of adjacent chalcogen elements sulfur and tellurium...
(Se) - SodiumSodiumSodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...
(Na) - SulfurSulfurSulfur or sulphur is the chemical element with atomic number 16. In the periodic table it is represented by the symbol S. It is an abundant, multivalent non-metal. Under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a bright yellow...
(S) numerous roles - ZincZincZinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
(Zn)
The required quantity varies widely between nutrients. At one extreme, a 70 kg human contains 1.0 kg of calcium, but only 3 mg of cobalt.
Elements with speculated role in human health
Many elements have been implicated at various times to have a role in human health. For none of these elements, however, has a specific protein, complex or dietary reference intakeDietary Reference Intake
The Dietary Reference Intake is a system of nutrition recommendations from the Institute of Medicine of the U.S. National Academy of Sciences. The DRI system is used by both the United States and Canada and is intended for the general public and health professionals...
been established:
- ArsenicArsenicArsenic is a chemical element with the symbol As, atomic number 33 and relative atomic mass 74.92. Arsenic occurs in many minerals, usually in conjunction with sulfur and metals, and also as a pure elemental crystal. It was first documented by Albertus Magnus in 1250.Arsenic is a metalloid...
(As) - BoronBoronBoron is the chemical element with atomic number 5 and the chemical symbol B. Boron is a metalloid. Because boron is not produced by stellar nucleosynthesis, it is a low-abundance element in both the solar system and the Earth's crust. However, boron is concentrated on Earth by the...
(B) - SiliconSiliconSilicon is a chemical element with the symbol Si and atomic number 14. A tetravalent metalloid, it is less reactive than its chemical analog carbon, the nonmetal directly above it in the periodic table, but more reactive than germanium, the metalloid directly below it in the table...
(Si)
Further reading
- Hausman, P, 1987, The Right Dose. Rodale Press, Emaus, Pennsylvania. ISBN 0-87857-678-9
See also
- AvitaminosisAvitaminosisAvitaminosis is any disease caused by chronic or long-term vitamin deficiency or caused by a defect in metabolic conversion, such as tryptophan to niacin...
(vitamin deficiency) - Dietary Reference IntakeDietary Reference IntakeThe Dietary Reference Intake is a system of nutrition recommendations from the Institute of Medicine of the U.S. National Academy of Sciences. The DRI system is used by both the United States and Canada and is intended for the general public and health professionals...
- Dietary supplementDietary supplementA dietary supplement, also known as food supplement or nutritional supplement, is a preparation intended to supplement the diet and provide nutrients, such as vitamins, minerals, fiber, fatty acids, or amino acids, that may be missing or may not be consumed in sufficient quantities in a person's diet...
- Illnesses related to poor nutritionIllnesses related to poor nutritionNutritional diseases are diseases in humans that are directly or indirectly caused by a lack of essential nutrients in the diet. Nutritional diseases are commonly associated with chronic malnutrition. Additionally, conditions such as obesity from overeating can also cause, or contribute to, serious...
- MalnutritionMalnutritionMalnutrition is the condition that results from taking an unbalanced diet in which certain nutrients are lacking, in excess , or in the wrong proportions....
- Orthomolecular medicineOrthomolecular medicineOrthomolecular medicine is a form of complementary and alternative medicine that seeks to maintain health and prevent or treat diseases by optimizing nutritional intake and/or prescribing supplements...
- Vitamin poisoningVitamin poisoningVitamin poisoning, hypervitaminosis or vitamin overdose refers to a condition of high storage levels of vitamins, which can lead to toxic symptoms...
- Health freedom movement
- MalabsorptionMalabsorptionMalabsorption is a state arising from abnormality in absorption of food nutrients across the gastrointestinal tract.Impairment can be of single or multiple nutrients depending on the abnormality...