A vitamin is an
organic molecule
In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. Th ...
(or a set of molecules closely related chemically, i.e.
vitamer
Vitamins occur in a variety of related forms known as vitamers. A vitamer () of a particular vitamin is one of several related compounds that performs the functions of said vitamin and prevents the symptoms of deficiency of said vitamin.
Early r ...
s) that is an
essential micronutrient that an
organism
In biology, an organism () is any living system that functions as an individual entity. All organisms are composed of cells (cell theory). Organisms are classified by taxonomy into groups such as multicellular animals, plants, and ...
needs in small quantities for the proper functioning of its
metabolism
Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cell ...
. Essential nutrients cannot be
synthesized in the organism, either at all or not in sufficient quantities, and therefore must be obtained through the
diet
Diet may refer to:
Food
* Diet (nutrition), the sum of the food consumed by an organism or group
* Dieting, the deliberate selection of food to control body weight or nutrient intake
** Diet food, foods that aid in creating a diet for weight loss ...
.
Vitamin C
Vitamin C (also known as ascorbic acid and ascorbate) is a water-soluble vitamin found in citrus and other fruits and vegetables, also sold as a dietary supplement and as a topical 'serum' ingredient to treat melasma (dark pigment spots) an ...
can be synthesized by some species but not by others; it is not a vitamin in the first instance but is in the second. The term ''vitamin'' does not include the three other groups of
essential nutrient
A nutrient is a substance used by an organism to survive, grow, and reproduce. The requirement for dietary nutrient intake applies to animals, plants, fungi, and protists. Nutrients can be incorporated into cells for metabolic purposes or excret ...
s:
minerals
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2 ...
,
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.
Only two fatty acids are known to be essential for humans: alpha-linolenic ac ...
s, and
essential amino acid
An essential amino acid, or indispensable amino acid, is an amino acid that cannot be synthesized from scratch by the organism fast enough to supply its demand, and must therefore come from the diet. Of the 21 amino acids common to all life form ...
s. Most vitamins are not single molecules, but groups of related molecules called vitamers. For example, there are eight vitamers of
vitamin E
Vitamin E is a group of eight fat soluble compounds that include four tocopherols and four tocotrienols. Vitamin E deficiency, which is rare and usually due to an underlying problem with digesting dietary fat rather than from a diet low in vitami ...
: four
tocopherol
Tocopherols (; TCP) are a class of organic chemical compounds (more precisely, various methylated phenols), many of which have vitamin E activity. Because the vitamin activity was first identified in 1936 from a dietary fertility factor in rat ...
s and four
tocotrienol
The vitamin E family comprise four tocotrienols (alpha, beta, gamma, delta) and four tocopherols (alpha, beta, gamma, delta). The critical chemical structural difference between tocotrienols and tocopherols is that tocotrienols have unsaturated i ...
s. Some sources list fourteen vitamins, by including
choline Choline is an essential nutrient for humans and many other animals. Choline occurs as a cation that forms various salts (X− in the depicted formula is an undefined counteranion). Humans are capable of some ''de novo synthesis'' of choline but r ...
, but major health organizations list thirteen:
vitamin A
Vitamin A is a fat-soluble vitamin and an essential nutrient for humans. It is a group of organic compounds that includes retinol, retinal (also known as retinaldehyde), retinoic acid, and several provitamin A carotenoids (most notably bet ...
(as all-''trans''-
retinol
Retinol, also called vitamin A1, is a fat-soluble vitamin in the vitamin A family found in food and used as a dietary supplement. As a supplement it is used to treat and prevent vitamin A deficiency, especially that which results in xeroph ...
, all-''trans''-retinyl-esters, as well as all-''trans''-
beta-carotene and other
provitamin A provitamin is a substance that may be converted within the body to a vitamin. The term previtamin is a synonym.
The term "provitamin" is used when it is desirable to label a substance with little or no vitamin activity, but which can be converted ...
A carotenoids), vitamin B
1 (
thiamine
Thiamine, also known as thiamin and vitamin B1, is a vitamin, an essential micronutrient, that cannot be made in the body. It is found in food and commercially synthesized to be a dietary supplement or medication. Phosphorylated forms of thi ...
), vitamin B
2 (
riboflavin
Riboflavin, also known as vitamin B2, is a vitamin found in food and sold as a dietary supplement. It is essential to the formation of two major coenzymes, flavin mononucleotide and flavin adenine dinucleotide. These coenzymes are involved in ...
), vitamin B
3 (
niacin
Niacin, also known as nicotinic acid, is an organic compound and a form of vitamin B3, an essential human nutrient. It can be manufactured by plants and animals from the amino acid tryptophan. Niacin is obtained in the diet from a variet ...
), vitamin B
5 (
pantothenic acid
Pantothenic acid, also called vitamin B5 is a water-soluble B vitamin and therefore an essential nutrient. All animals require pantothenic acid in order to synthesize coenzyme A (CoA) – essential for fatty acid metabolism – as well as to, i ...
), vitamin B
6 (
pyridoxine
Pyridoxine, is a form of vitamin B6 found commonly in food and used as a dietary supplement. As a supplement it is used to treat and prevent pyridoxine deficiency, sideroblastic anaemia, pyridoxine-dependent epilepsy, certain metabolic disorde ...
), vitamin B
7 (
biotin
Biotin (or vitamin B7) is one of the B vitamins. It is involved in a wide range of metabolic processes, both in humans and in other organisms, primarily related to the utilization of fats, carbohydrates, and amino acids. The name ''biotin'', bor ...
), vitamin B
9 (
folic acid
Folate, also known as vitamin B9 and folacin, is one of the B vitamins. Manufactured folic acid, which is converted into folate by the body, is used as a dietary supplement and in food fortification as it is more stable during processing and ...
or
folate
Folate, also known as vitamin B9 and folacin, is one of the B vitamins. Manufactured folic acid, which is converted into folate by the body, is used as a dietary supplement and in food fortification as it is more stable during processing and ...
), vitamin B
12 (
cobalamin
Vitamin B12, also known as cobalamin, is a water-soluble vitamin involved in metabolism. It is one of eight B vitamins. It is required by animals, which use it as a cofactor in DNA synthesis, in both fatty acid and amino acid metabolism. It ...
s), vitamin C (
ascorbic acid
Vitamin C (also known as ascorbic acid and ascorbate) is a water-soluble vitamin found in citrus and other fruits and vegetables, also sold as a dietary supplement and as a topical 'serum' ingredient to treat melasma (dark pigment spots) an ...
),
vitamin D
Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and many other biological effects. In humans, the most important compounds in this group are vitamin D3 (c ...
(calciferols), vitamin E (tocopherols and tocotrienols), and
vitamin K
Vitamin K refers to structurally similar, fat-soluble vitamers found in foods and marketed as dietary supplements. The human body requires vitamin K for post-synthesis modification of certain proteins that are required for blood coagulation ...
(
phylloquinone
Phytomenadione, also known as vitamin K1 or phylloquinone, is a vitamin found in food and used as a dietary supplement. It is on the World Health Organization's List of Essential Medicines.
As a supplement it is used to treat certain bleeding ...
and
menaquinone
Vitamin K2 or menaquinone (MK) () is one of three types of vitamin K
Vitamin K refers to structurally similar, fat-soluble vitamers found in foods and marketed as dietary supplements. The human body requires vitamin K for post-synthesis ...
s).
Vitamins have diverse biochemical functions. Vitamin A acts as a regulator of cell and tissue growth and differentiation. Vitamin D provides a hormone-like function, regulating mineral metabolism for bones and other organs. The
B complex
B vitamins are a class of water-soluble vitamins that play important roles in cell metabolism and synthesis of red blood cells. Though these vitamins share similar names (B1, B2, B3, etc.), they are chemically distinct compounds that often coexist ...
vitamins function as enzyme
cofactors (coenzymes) or the
precursors for them. Vitamins C and E function as
antioxidant
Antioxidants are compounds that inhibit oxidation, a chemical reaction that can produce free radicals. This can lead to polymerization and other chain reactions. They are frequently added to industrial products, such as fuels and lubricant ...
s.
Both deficient and excess intake of a vitamin can potentially cause clinically significant illness, although excess intake of water-soluble vitamins is less likely to do so.
All vitamins were discovered (identified) between 1913 and 1948. Historically, when intake of vitamins from diet was lacking, the results were vitamin deficiency diseases. Then, starting in 1935, commercially produced tablets of yeast-extract vitamin B complex and semi-synthetic vitamin C became available.
This was followed in the 1950s by the mass production and marketing of
vitamin supplement
A multivitamin is a preparation intended to serve as a dietary supplement with vitamins, dietary minerals, and other nutritional elements. Such preparations are available in the form of tablets, capsules, pastilles, powders, liquids, or injectab ...
s, including
multivitamins, to prevent vitamin deficiencies in the general population.
Governments have mandated the addition of some vitamins to
staple food
A staple food, food staple, or simply a staple, is a food that is eaten often and in such quantities that it constitutes a dominant portion of a standard diet for a given person or group of people, supplying a large fraction of energy needs and ...
s such as flour or milk, referred to as
food fortification
Food fortification or enrichment is the process of adding micronutrients (essential trace elements and vitamins) to food. It can be carried out by food manufacturers, or by governments as a public health policy which aims to reduce the number of p ...
, to prevent deficiencies.
Recommendations for folic acid supplementation during
pregnancy
Pregnancy is the time during which one or more offspring develops ( gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins.
Pregnancy usually occurs by sexual intercourse, but ca ...
reduced risk of infant
neural tube defect
Neural tube defects (NTDs) are a group of birth defects in which an opening in the spine or cranium remains from early in human development. In the third week of pregnancy called gastrulation, specialized cells on the dorsal side of the embryo ...
s.
List of vitamins
History
The value of eating certain foods to maintain health was recognized long before vitamins were identified. The
ancient Egyptians knew that feeding
liver
The liver is a major Organ (anatomy), organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of proteins and biochemicals necessary for ...
to a person may help with
night blindness
Nyctalopia (; ), also called night-blindness, is a condition making it difficult or impossible to see in relatively low light. It is a symptom of several eye diseases. Night blindness may exist from birth, or be caused by injury or malnutrition ( ...
, an illness now known to be caused by a
vitamin A
Vitamin A is a fat-soluble vitamin and an essential nutrient for humans. It is a group of organic compounds that includes retinol, retinal (also known as retinaldehyde), retinoic acid, and several provitamin A carotenoids (most notably bet ...
deficiency.
The advancement of ocean voyages during the
Age of Discovery
The Age of Discovery (or the Age of Exploration), also known as the early modern period, was a period largely overlapping with the Age of Sail, approximately from the 15th century to the 17th century in European history, during which seafarin ...
resulted in prolonged periods without access to fresh fruits and vegetables, and made illnesses from vitamin deficiency common among ships' crews.
In 1747, the
Scottish surgeon
In modern medicine, a surgeon is a medical professional who performs surgery. Although there are different traditions in different times and places, a modern surgeon usually is also a licensed physician or received the same medical training as ...
James Lind
James Lind (4 October 1716 – 13 July 1794) was a Scottish doctor. He was a pioneer of naval hygiene in the Royal Navy. By conducting one of the first ever clinical trials, he developed the theory that citrus fruits cured scurvy.
Lind arg ...
discovered that
citrus
''Citrus'' is a genus of flowering plant, flowering trees and shrubs in the rue family, Rutaceae. Plants in the genus produce citrus fruits, including important crops such as Orange (fruit), oranges, Lemon, lemons, grapefruits, pomelos, and lim ...
foods helped prevent scurvy, a particularly deadly disease in which
collagen
Collagen () is the main structural protein in the extracellular matrix found in the body's various connective tissues. As the main component of connective tissue, it is the most abundant protein in mammals, making up from 25% to 35% of the whole ...
is not properly formed, causing poor wound healing, bleeding of the
gums
The gums or gingiva (plural: ''gingivae'') consist of the mucosal tissue that lies over the mandible and maxilla inside the mouth. Gum health and disease can have an effect on general health.
Structure
The gums are part of the soft tissue lin ...
, severe pain, and death.
[Jack Challem (1997]
"The Past, Present and Future of Vitamins"
In 1753, Lind published his ''Treatise on the Scurvy'', which recommended using
lemon
The lemon (''Citrus limon'') is a species of small evergreen trees in the flowering plant family Rutaceae, native to Asia, primarily Northeast India (Assam), Northern Myanmar or China.
The tree's ellipsoidal yellow fruit is used for culin ...
s and
lime
Lime commonly refers to:
* Lime (fruit), a green citrus fruit
* Lime (material), inorganic materials containing calcium, usually calcium oxide or calcium hydroxide
* Lime (color), a color between yellow and green
Lime may also refer to:
Botany ...
s to avoid
scurvy
Scurvy is a disease resulting from a lack of vitamin C (ascorbic acid). Early symptoms of deficiency include weakness, feeling tired and sore arms and legs. Without treatment, decreased red blood cells, gum disease, changes to hair, and bleeding ...
, which was adopted by the British
Royal Navy
The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against F ...
. This led to the nickname ''
limey
"Limey" (from lime / lemon) is a predominantly American slang nickname for a British person that has been around since the mid 19th century.[Arctic
The Arctic ( or ) is a polar regions of Earth, polar region located at the northernmost part of Earth. The Arctic consists of the Arctic Ocean, adjacent seas, and parts of Canada (Yukon, Northwest Territories, Nunavut), Danish Realm (Greenla ...]
expeditions in the 19th century, where it was widely believed that scurvy could be prevented by practicing good
hygiene
Hygiene is a series of practices performed to preserve health.
According to the World Health Organization (WHO), "Hygiene refers to conditions and practices that help to maintain health and prevent the spread of diseases." Personal hygiene refer ...
, regular exercise, and maintaining the
morale
Morale, also known as esprit de corps (), is the capacity of a group's members to maintain belief in an institution or goal, particularly in the face of opposition or hardship. Morale is often referenced by authority figures as a generic value ...
of the crew while on board, rather than by a diet of fresh food.
As a result, Arctic expeditions continued to be plagued by scurvy and other
deficiency disease
Malnutrition occurs when an organism gets too few or too many nutrients, resulting in health problems. Specifically, it is "a deficiency, excess, or imbalance of energy, protein and other nutrients" which adversely affects the body's tissues ...
s. In the early 20th century, when
Robert Falcon Scott
Captain Robert Falcon Scott, , (6 June 1868 – c. 29 March 1912) was a British Royal Navy officer and explorer who led two expeditions to the Antarctic regions: the ''Discovery'' expedition of 1901–1904 and the ill-fated ''Terra Nov ...
made his two expeditions to the
Antarctic
The Antarctic ( or , American English also or ; commonly ) is a polar region around Earth's South Pole, opposite the Arctic region around the North Pole. The Antarctic comprises the continent of Antarctica, the Kerguelen Plateau and other ...
, the prevailing medical theory at the time was that scurvy was caused by "tainted"
canned food
Canning is a method of food preservation in which food is processed and sealed in an airtight container ( jars like Mason jars, and steel and tin cans). Canning provides a shelf life that typically ranges from one to five years, although ...
.
During the late 18th and early 19th centuries, the use of deprivation studies allowed scientists to isolate and identify a number of vitamins. Lipid from
fish oil
Fish oil is oil derived from the tissues of oily fish. Fish oils contain the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), precursors of certain eicosanoids that are known to reduce inflammation in the b ...
was used to cure
rickets
Rickets is a condition that results in weak or soft bones in children, and is caused by either dietary deficiency or genetic causes. Symptoms include bowed legs, stunted growth, bone pain, large forehead, and trouble sleeping. Complications may ...
in
rats, and the fat-soluble nutrient was called "antirachitic A". Thus, the first "vitamin" bioactivity ever isolated, which cured rickets, was initially called "vitamin A"; however, the bioactivity of this compound is now called
vitamin D
Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and many other biological effects. In humans, the most important compounds in this group are vitamin D3 (c ...
. In 1881,
Russia
Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...
n medical doctor studied the effects of scurvy at the
University of Tartu
The University of Tartu (UT; et, Tartu Ülikool; la, Universitas Tartuensis) is a university in the city of Tartu in Estonia. It is the national university of Estonia. It is the only classical university in the country, and also its biggest ...
. He fed mice an artificial mixture of all the separate constituents of milk known at that time, namely the
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
s,
fat
In nutrition science, nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such chemical compound, compounds, most commonly those that occur in living beings or in food.
The term often refers spec ...
s,
carbohydrate
In organic chemistry, a carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where ''m'' may or ma ...
s, and
salt
Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quantitie ...
s. The mice that received only the individual constituents died, while the mice fed by milk itself developed normally. He made a conclusion that "a natural food such as milk must therefore contain, besides these known principal ingredients, small quantities of unknown substances essential to life." However, his conclusions were rejected by his advisor,
Gustav von Bunge.
A similar result by Cornelius Pekelharing appeared in a Dutch medical journal in 1905, but it was not widely reported.
[
In ]East Asia
East Asia is the eastern region of Asia, which is defined in both geographical and ethno-cultural terms. The modern states of East Asia include China, Japan, Mongolia, North Korea, South Korea, and Taiwan. China, North Korea, South Korea and ...
, where polished white rice
White rice is milled rice that has had its husk, bran, and germ removed. This alters the flavor, texture and appearance of the rice and helps prevent spoilage, extend its storage life, and makes it easier to digest. After milling (hulling), the ...
was the common staple food of the middle class, beriberi
Thiamine deficiency is a medical condition of low levels of thiamine (Vitamin B1). A severe and chronic form is known as beriberi. The two main types in adults are wet beriberi and dry beriberi. Wet beriberi affects the cardiovascular system, ...
resulting from lack of vitamin B1 was endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...
. In 1884, Takaki Kanehiro
Baron was a Japanese naval physician.
Early life
Born in Hyūga Province (present-day Miyazaki Prefecture) as the son of a '' samurai'' retainer to the Satsuma domain, Takaki studied Chinese medicine as a youth and served as a medic in the ...
, a British-trained medical doctor of the Imperial Japanese Navy
The Imperial Japanese Navy (IJN; Kyūjitai: Shinjitai: ' 'Navy of the Greater Japanese Empire', or ''Nippon Kaigun'', 'Japanese Navy') was the navy of the Empire of Japan from 1868 to 1945, when it was dissolved following Japan's surrender ...
, observed that beriberi was endemic among low-ranking crew who often ate nothing but rice, but not among officers who consumed a Western-style diet. With the support of the Japanese navy, he experimented using crews of two battleship
A battleship is a large armored warship with a main battery consisting of large caliber guns. It dominated naval warfare in the late 19th and early 20th centuries.
The term ''battleship'' came into use in the late 1880s to describe a type of ...
s; one crew was fed only white rice, while the other was fed a diet of meat, fish, barley, rice, and beans. The group that ate only white rice documented 161 crew members with beriberi and 25 deaths, while the latter group had only 14 cases of beriberi and no deaths. This convinced Takaki and the Japanese Navy that diet was the cause of beriberi, but they mistakenly believed that sufficient amounts of protein prevented it. That diseases could result from some dietary deficiencies was further investigated by Christiaan Eijkman
Christiaan Eijkman ( , , ; 11 August 1858 – 5 November 1930) was a Dutch physician and professor of physiology whose demonstration that beriberi is caused by poor diet led to the discovery of antineuritic vitamins (thiamine). Together with S ...
, who in 1897 discovered that feeding unpolished rice
Rice is the seed of the grass species ''Oryza sativa'' (Asian rice) or less commonly ''Oryza glaberrima
''Oryza glaberrima'', commonly known as African rice, is one of the two domesticated rice species. It was first domesticated and grown i ...
instead of the polished variety to chickens helped to prevent a kind of polyneuritis
Peripheral neuropathy, often shortened to neuropathy, is a general term describing disease affecting the peripheral nerves, meaning nerves beyond the brain and spinal cord. Damage to peripheral nerves may impair sensation, movement, gland, or o ...
that was the equivalent of beriberi. The following year, Frederick Hopkins postulated that some foods contained "accessory factors" — in addition to proteins, carbohydrates, fats ''etc.'' — that are necessary for the functions of the human body.
"Vitamine" to vitamin
In 1910, the first vitamin complex was isolated by Japanese scientist Umetaro Suzuki
was a Japanese scientist, born in what is now part of Makinohara, Shizuoka, Japan. He was a member of the Imperial Academy, and a recipient of the Grand Cordon of the Order of the Sacred Treasure and the Order of Culture. His research was among t ...
, who succeeded in extracting a water-soluble complex of micronutrients from rice bran and named it aberic acid (later ''Orizanin''). He published this discovery in a Japanese scientific journal. When the article was translated into German, the translation failed to state that it was a newly discovered nutrient, a claim made in the original Japanese article, and hence his discovery failed to gain publicity. In 1912 Polish-born biochemist Casimir Funk
Kazimierz Funk (; February 23, 1884 – November 19, 1967), commonly anglicized as Casimir Funk, was a Polish-American biochemist generally credited with being among the first to formulate (in 1912) the concept of vitamins, which he called "vit ...
, working in London, isolated the same complex of micronutrients and proposed the complex be named "vitamine". It was later to be known as vitamin B3 (niacin), though he described it as "anti-beri-beri-factor" (which would today be called thiamine or vitamin B1). Funk proposed the hypothesis that other diseases, such as rickets, pellagra, coeliac disease, and scurvy could also be cured by vitamins. Max Nierenstein a friend and Reader of Biochemistry at Bristol University reportedly suggested the "vitamine" name (from "vital amine"). The name soon became synonymous with Hopkins' "accessory factors", and, by the time it was shown that not all vitamins are amine
In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen atoms have been replaced by a substituen ...
s, the word was already ubiquitous. In 1920, Jack Cecil Drummond
Sir Jack Cecil Drummond FRIC, FRS (12 January 1891 – 4/5 August 1952) was a distinguished biochemist, noted for his work on nutrition as applied to the British diet under rationing during the Second World War. He was murdered, together with ...
proposed that the final "e" be dropped to deemphasize the "amine" reference, hence "vitamin," after researchers began to suspect that not all "vitamines" (in particular, vitamin A) have an amine component.[
]
Nobel Prizes for vitamin research
The Nobel Prize for Chemistry for 1928 was awarded to Adolf Windaus
Adolf Otto Reinhold Windaus (; 25 December 1876 – 9 June 1959) was a German chemist who won a Nobel Prize in Chemistry in 1928 for his work on sterols and their relation to vitamins. He was the doctoral advisor of Adolf Butenandt who also won ...
"for his studies on the constitution of the sterols and their connection with vitamins", the first person to receive an award mentioning vitamins, even though it was not specifically about vitamin D.
The Nobel Prize in Physiology or Medicine
The Nobel Prize in Physiology or Medicine is awarded yearly by the Nobel Assembly at the Karolinska Institute for outstanding discoveries in physiology or medicine. The Nobel Prize is not a single prize, but five separate prizes that, accord ...
for 1929 was awarded to Christiaan Eijkman and Frederick Gowland Hopkins
Sir Frederick Gowland Hopkins (20 June 1861 – 16 May 1947) was an English biochemist who was awarded the Nobel Prize in Physiology or Medicine in 1929, with Christiaan Eijkman, for the discovery of vitamins, even though Casimir Funk, a Po ...
for their contributions to the discovery of vitamins. Thirty-five years earlier, Eijkman had observed that chickens fed polished white rice developed neurological symptoms similar to those observed in military sailors and soldiers fed a rice-based diet, and that the symptoms were reversed when the chickens were switched to whole-grain rice. He called this "the anti-beriberi factor", which was later identified as vitamin B1, thiamine.
In 1930, Paul Karrer
Paul may refer to:
*Paul (given name), a given name (includes a list of people with that name)
* Paul (surname), a list of people
People
Christianity
*Paul the Apostle (AD c.5–c.64/65), also known as Saul of Tarsus or Saint Paul, early Chri ...
elucidated the correct structure for beta-carotene, the main precursor of vitamin A, and identified other carotenoids
Carotenoids (), also called tetraterpenoids, are yellow, orange, and red organic pigments that are produced by plants and algae, as well as several bacteria, and fungi. Carotenoids give the characteristic color to pumpkins, carrots, parsnips, ...
. Karrer and Norman Haworth
Sir Walter Norman Haworth FRS (19 March 1883 – 19 March 1950) was a British chemist best known for his groundbreaking work on ascorbic acid ( vitamin C) while working at the University of Birmingham. He received the 1937 Nobel Prize in Chem ...
confirmed Albert Szent-Györgyi's discovery of ascorbic acid
Vitamin C (also known as ascorbic acid and ascorbate) is a water-soluble vitamin found in citrus and other fruits and vegetables, also sold as a dietary supplement and as a topical 'serum' ingredient to treat melasma (dark pigment spots) an ...
and made significant contributions to the chemistry of flavins
Flavins (from Latin ''flavus'', "yellow") are organic compounds, like their base, pteridine. They are formed by the tricyclic heterocycle isoalloxazine. The biochemical source is the vitamin riboflavin. The flavin moiety is often attached with ...
, which led to the identification of lactoflavin
Riboflavin, also known as vitamin B2, is a vitamin found in food and sold as a dietary supplement. It is essential to the formation of two major coenzymes, flavin mononucleotide and flavin adenine dinucleotide. These coenzymes are involved in e ...
. For their investigations on carotenoids, flavins and vitamins A and B2, they both received the Nobel Prize in Chemistry
)
, image = Nobel Prize.png
, alt = A golden medallion with an embossed image of a bearded man facing left in profile. To the left of the man is the text "ALFR•" then "NOBEL", and on the right, the text (smaller) "NAT•" then "M ...
in 1937.
In 1931, Albert Szent-Györgyi
Albert Imre Szent-Györgyi de Nagyrápolt ( hu, nagyrápolti Szent-Györgyi Albert Imre; September 16, 1893 – October 22, 1986) was a Hungarian biochemist who won the Nobel Prize in Physiology or Medicine in 1937. He is credited with fi ...
and a fellow researcher Joseph Svirbely
Joseph is a common male given name, derived from the Hebrew Yosef (יוֹסֵף). "Joseph" is used, along with "Josef", mostly in English, French and partially German languages. This spelling is also found as a variant in the languages of the mo ...
suspected that "hexuronic acid" was actually vitamin C
Vitamin C (also known as ascorbic acid and ascorbate) is a water-soluble vitamin found in citrus and other fruits and vegetables, also sold as a dietary supplement and as a topical 'serum' ingredient to treat melasma (dark pigment spots) an ...
, and gave a sample to Charles Glen King, who proved its activity counter to scurvy in his long-established guinea pig
The guinea pig or domestic guinea pig (''Cavia porcellus''), also known as the cavy or domestic cavy (), is a species of rodent belonging to the genus ''Cavia'' in the family Caviidae. Breeders tend to use the word ''cavy'' to describe the ani ...
scorbutic assay. In 1937, Szent-Györgyi was awarded the Nobel Prize in Physiology or Medicine for his discovery. In 1943, Edward Adelbert Doisy
Edward Adelbert Doisy (November 13, 1893 – October 23, 1986) was an American biochemist. He received the Nobel Prize in Physiology or Medicine in 1943 with Henrik Dam for their discovery of vitamin K (K from "Koagulations-Vitamin" in German) an ...
and Henrik Dam
Carl Peter Henrik Dam ( da, Carl Peter Henrik Dam), (21 February 1895 – 17 April 1976) was a Danish biochemist and physiologist.
He was awarded the Nobel Prize in Medicine in 1943 for joint work with Edward Doisy in discovering vitamin ...
were awarded the Nobel Prize in Physiology or Medicine for their discovery of vitamin K
Vitamin K refers to structurally similar, fat-soluble vitamers found in foods and marketed as dietary supplements. The human body requires vitamin K for post-synthesis modification of certain proteins that are required for blood coagulation ...
and its chemical structure.
In 1938, Richard Kuhn
Richard Johann Kuhn (; 3 December 1900 – 1 August 1967) was an Austrian-German biochemist who was awarded the Nobel Prize in Chemistry in 1938 "for his work on carotenoids and vitamins".
Biography
Early life
Kuhn was born in Vienna, Austr ...
was awarded the Nobel Prize in Chemistry for his work on carotenoids and vitamins, specifically B2 and B6.
Five people have been awarded Nobel Prize
The Nobel Prizes ( ; sv, Nobelpriset ; no, Nobelprisen ) are five separate prizes that, according to Alfred Nobel's will of 1895, are awarded to "those who, during the preceding year, have conferred the greatest benefit to humankind." Alfr ...
s for direct and indirect studies of vitamin B12: George Whipple
George Hoyt Whipple (August 28, 1878 – February 1, 1976) was an American physician, pathologist, biomedical researcher, and medical school educator and administrator. Whipple shared the Nobel Prize in Physiology or Medicine in 1934 with George ...
, George Minot
George Richards Minot (December 2, 1885 – February 25, 1950) was an American medical researcher who shared the 1934 Nobel Prize with George Hoyt Whipple and William P. Murphy for their pioneering work on pernicious anemia.
Early life
George R ...
and William P. Murphy (1934), Alexander R. Todd
Alexander Robertus Todd, Baron Todd (2 October 1907 – 10 January 1997) was a British people, British biochemist whose research on the structure and biosynthesis, synthesis of nucleotides, nucleosides, and nucleotide coenzymes gained him the N ...
(1957), and Dorothy Hodgkin
Dorothy Mary Crowfoot Hodgkin (née Crowfoot; 12 May 1910 – 29 July 1994) was a Nobel Prize-winning British chemist who advanced the technique of X-ray crystallography to determine the structure of biomolecules, which became essential fo ...
(1964).
In 1967, George Wald, Ragnar Granit
Ragnar Arthur Granit (30 October 1900 – 12 March 1991) was a Finnish-Swedish scientist who was awarded the Nobel Prize in Physiology or Medicine in 1967 along with Haldan Keffer Hartline and George Wald "for their discoveries concerning the ...
and Haldan Keffer Hartline
Haldan Keffer Hartline (December 22, 1903 – March 17, 1983) was an American physiologist who was a co-recipient (with George Wald and Ragnar Granit) of the 1967 Nobel Prize in Physiology or Medicine for his work in analyzing the neurophysiolog ...
were awarded the Nobel Prize in Physiology and Medicine "...for their discoveries concerning the primary physiological and chemical visual processes in the eye." Wald's contribution was discovering the role vitamin A had in the process.
History of promotional marketing
Once discovered, vitamins were actively promoted in articles and advertisements in ''McCall's
''McCall's'' was a monthly American women's magazine, published by the McCall Corporation, that enjoyed great popularity through much of the 20th century, peaking at a readership of 8.4 million in the early 1960s. It was established as a small-f ...
'', ''Good Housekeeping
''Good Housekeeping'' is an American women's magazine featuring articles about women's interests, product testing by The Good Housekeeping Institute, recipes, diet, and health, as well as literary articles. It is well known for the "Good House ...
'', and other media outlets. Marketers enthusiastically promoted cod-liver oil
Cod liver oil is a dietary supplement derived from liver of cod fish (Gadidae). As with most fish oils, it contains the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and also vitamin A and vitamin D. Histori ...
, a source of vitamin D, as "bottled sunshine", and bananas as a "natural vitality food". They promoted foods such as yeast
Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are estimated to constitut ...
cakes, a source of B vitamins, on the basis of scientifically determined nutritional value, rather than taste or appearance. In 1942, when flour enrichment with nicotinic acid began, a headline in the popular press said "Tobacco in Your Bread." In response, the Council on Foods and Nutrition of the American Medical Association
The American Medical Association (AMA) is a professional association and lobbying group of physicians and medical students. Founded in 1847, it is headquartered in Chicago, Illinois. Membership was approximately 240,000 in 2016.
The AMA's state ...
approved of the Food and Nutrition Board
The Dietary Reference Intake (DRI) is a system of nutrition recommendations from the National Academy of Medicine (NAM) of the National Academies (United States). It was introduced in 1997 in order to broaden the existing guidelines known as Reco ...
's new names ''niacin'' and ''niacin amide'' for use primarily by non-scientists. It was thought appropriate to choose a name to dissociate nicotinic acid from nicotine
Nicotine is a natural product, naturally produced alkaloid in the nightshade family of plants (most predominantly in tobacco and ''Duboisia hopwoodii'') and is widely used recreational drug use, recreationally as a stimulant and anxiolytic. As ...
, to avoid the perception that vitamins or niacin-rich food contains nicotine, or that cigarettes contain vitamins. The resulting name ''niacin'' was derived from ''cotinic id'' + ''vitam''. Researchers also focused on the need to ensure adequate nutrition, especially to compensate for what was lost in the manufacture of processed foods
Convenience food, also called tertiary processed food, is food that is commercially prepared (often through processing) to optimise ease of consumption. Such food is usually ready to eat without further preparation. It may also be easily por ...
.
Robert W. Yoder is credited with first using the term ''vitamania'', in 1942, to describe the appeal of relying on nutritional supplements rather than on obtaining vitamins from a varied diet of foods. The continuing preoccupation with a healthy lifestyle led to an obsessive consumption of vitamins and multi-vitamins, the beneficial effects of which are questionable. As one example, in the 1950s, the Wonder Bread
Wonder Bread is a brand of sliced bread which originated in the United States in 1921 and was one of the first to be sold pre-sliced nationwide in 1930. The brand is currently owned by Flowers Foods in the United States.
History
The Taggart B ...
company sponsored the Howdy Doody
''Howdy Doody'' is an American Children's television series, children's television program (with circus and Western (genre), Western frontier themes) that was created and produced by Victor F Campbell television show, with host Buffalo Bob Smith
Robert Emil Schmidt (November 27, 1917 – July 30, 1998), nicknamed Buffalo Bob, was the host of the children's show ''Howdy Doody''.
Biography
Born in Buffalo, New York, as Robert Emil Schmidt, he attended Masten Park High School.
Schmidt g ...
telling the audience, "Wonder Bread builds strong bodies 8 ways", referring to the number of added nutrients.
Etymology
The term "vitamin" was derived from "vitamine", a compound word
In linguistics, a compound is a lexeme (less precisely, a word or sign) that consists of more than one stem. Compounding, composition or nominal composition is the process of word formation that creates compound lexemes. Compounding occurs when ...
coined in 1912 by the biochemist
Biochemists are scientists who are trained in biochemistry. They study chemical processes and chemical transformations in living organisms. Biochemists study DNA, proteins and Cell (biology), cell parts. The word "biochemist" is a portmanteau of ...
Casimir Funk while working at the Lister Institute of Preventive Medicine
The Lister Institute of Preventive Medicine, informally known as the Lister Institute, was established as a research institute (the British Institute of Preventive Medicine) in 1891, with bacteriologist Marc Armand Ruffer as its first director, u ...
.[ The word "vitamine" is coined on p. 342: "It is now known that all these diseases, with the exception of pellagra, can be prevented and cured by the addition of certain preventative substances; the deficient substances, which are of the nature of organic bases, we will call "vitamines"; and we will speak of a beri-beri or scurvy vitamine, which means a substance preventing the special disease."] Funk created the name from ''vital'' and ''amine'', because it appeared that these organic micronutrient food factors that prevent beriberi and perhaps other similar dietary-deficiency diseases were required for life, hence "vital", and were chemical amines, hence "amine". This was true of thiamine
Thiamine, also known as thiamin and vitamin B1, is a vitamin, an essential micronutrient, that cannot be made in the body. It is found in food and commercially synthesized to be a dietary supplement or medication. Phosphorylated forms of thi ...
, but after it was found that vitamin C and other such micronutrients were not amines, the word was shortened to "vitamin" in English.
Classification
Vitamins are classified as either water-soluble
In chemistry, solubility is the ability of a substance, the solute, to form a solution with another substance, the solvent. Insolubility is the opposite property, the inability of the solute to form such a solution.
The extent of the solub ...
or fat-soluble
Lipophilicity (from Greek λίπος "fat" and φίλος "friendly"), refers to the ability of a chemical compound to dissolve in fats, oils, lipids, and non-polar solvents such as hexane or toluene. Such non-polar solvents are themselves lipop ...
. In humans there are 13 vitamins: 4 fat-soluble (A, D, E, and K) and 9 water-soluble (8 B vitamins and vitamin C). Water-soluble vitamins dissolve easily in water and, in general, are readily excreted from the body, to the degree that urinary output is a strong predictor of vitamin consumption. Because they are not as readily stored, more consistent intake is important. Fat-soluble vitamins are absorbed through the intestinal tract
The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans ...
with the help of lipid
Lipids are a broad group of naturally-occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids include ...
s (fats). Vitamins A and D can accumulate in the body, which can result in dangerous hypervitaminosis
Hypervitaminosis is a condition of abnormally high storage levels of vitamins, which can lead to various symptoms as over excitement, irritability, or even toxicity. Specific medical names of the different conditions are derived from the given vit ...
. Fat-soluble vitamin deficiency due to malabsorption is of particular significance in cystic fibrosis
Cystic fibrosis (CF) is a rare genetic disorder that affects mostly the lungs, but also the pancreas, liver, kidneys, and intestine. Long-term issues include difficulty breathing and coughing up mucus as a result of frequent lung infections. O ...
.
Anti-vitamins
Anti-vitamins are chemical compounds that inhibit the absorption or actions of vitamins. For example, avidin
Avidin is a tetrameric biotin-binding protein produced in the oviducts of birds, reptiles and amphibians and deposited in the whites of their eggs. Dimeric members of the avidin family are also found in some bacteria. In chicken egg white, avidin ...
is a protein in raw egg whites that inhibits the absorption of biotin
Biotin (or vitamin B7) is one of the B vitamins. It is involved in a wide range of metabolic processes, both in humans and in other organisms, primarily related to the utilization of fats, carbohydrates, and amino acids. The name ''biotin'', bor ...
; it is deactivated by cooking. Pyrithiamine, a synthetic compound, has a molecular structure similar to thiamine, vitamin B1, and inhibits the enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...
s that use thiamine.
Biochemical functions
Each vitamin is typically used in multiple reactions, and therefore most have multiple functions.[Kutsky, R.J. (1973). Handbook of Vitamins and Hormones. New York: Van Nostrand Reinhold, ]
On fetal growth and childhood development
Vitamins are essential for the normal growth and development of a multicellular organism. Using the genetic blueprint inherited from its parents, a fetus
A fetus or foetus (; plural fetuses, feti, foetuses, or foeti) is the unborn offspring that develops from an animal embryo. Following embryonic development the fetal stage of development takes place. In human prenatal development, fetal deve ...
develop
Develop or DEVELOP may refer to:
* ''Develop'' (magazine), a trade publication for the video game industry
* ''Develop'' (Apple magazine), a technical magazine formerly published by Apple Computer
* Develop (chess), moving a piece from its origina ...
s from the nutrients it absorbs. It requires certain vitamins and minerals to be present at certain times. These nutrients facilitate the chemical reactions that produce among other things, skin
Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation.
Other cuticle, animal coverings, such as the arthropod exoskeleton, have diffe ...
, bone
A bone is a Stiffness, rigid Organ (biology), organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red blood cell, red and white blood cells, store minerals, provid ...
, and muscle
Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscl ...
. If there is serious deficiency in one or more of these nutrients, a child may develop a deficiency disease. Even minor deficiencies may cause permanent damage.
On adult health maintenance
Once growth and development are completed, vitamins remain essential nutrients for the healthy maintenance of the cells, tissues, and organs that make up a multicellular organism; they also enable a multicellular life form to efficiently use chemical energy provided by food it eats, and to help process the proteins, carbohydrates, and fats required for cellular respiration
Cellular respiration is the process by which biological fuels are oxidised in the presence of an inorganic electron acceptor such as oxygen to produce large amounts of energy, to drive the bulk production of ATP. Cellular respiration may be des ...
.
Intake
Sources
For the most part, vitamins are obtained from the diet, but some are acquired by other means: for example, microorganisms in the gut flora
Gut microbiota, gut microbiome, or gut flora, are the microorganisms, including bacteria, archaea, fungi, and viruses that live in the digestive tracts of animals. The gastrointestinal metagenome is the aggregate of all the genomes of the gut mi ...
produce vitamin K and biotin; and one form of vitamin D is synthesized in skin cells when they are exposed to a certain wavelength of ultraviolet light present in sunlight
Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light. On Earth, sunlight is scattered and filtered through Earth's atmosphere, and is obvious as daylight when t ...
. Humans can produce some vitamins from precursors they consume: for example, vitamin A is synthesized from beta carotene
Beta (, ; uppercase , lowercase , or cursive ; grc, βῆτα, bē̂ta or ell, βήτα, víta) is the second letter of the Greek alphabet. In the system of Greek numerals, it has a value of 2. In Modern Greek, it represents the voiced labio ...
; and niacin
Niacin, also known as nicotinic acid, is an organic compound and a form of vitamin B3, an essential human nutrient. It can be manufactured by plants and animals from the amino acid tryptophan. Niacin is obtained in the diet from a variet ...
is synthesized from the amino acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha am ...
tryptophan
Tryptophan (symbol Trp or W)
is an α-amino acid that is used in the biosynthesis of proteins. Tryptophan contains an α-amino group, an α- carboxylic acid group, and a side chain indole, making it a polar molecule with a non-polar aromatic ...
. Vitamin C can be synthesized by some species but not by others. Vitamin B12 is the only vitamin or nutrient not available from plant sources. The Food Fortification Initiative lists countries which have mandatory fortification programs for vitamins folic acid, niacin, vitamin A and vitamins B1, B2 and B12.
Deficient intake
The body's stores for different vitamins vary widely; vitamins A, D, and B12 are stored in significant amounts, mainly in the liver
The liver is a major Organ (anatomy), organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of proteins and biochemicals necessary for ...
, and an adult's diet may be deficient in vitamins A and D for many months and B12 in some cases for years, before developing a deficiency condition. However, vitamin B3 (niacin and niacinamide) is not stored in significant amounts, so stores may last only a couple of weeks. For vitamin C, the first symptoms of scurvy in experimental studies of complete vitamin C deprivation in humans have varied widely, from a month to more than six months, depending on previous dietary history that determined body stores.
Deficiencies of vitamins are classified as either primary or secondary. A primary deficiency occurs when an organism does not get enough of the vitamin in its food. A secondary deficiency may be due to an underlying disorder that prevents or limits the absorption or use of the vitamin, due to a "lifestyle factor", such as smoking, excessive alcohol consumption, or the use of medications that interfere with the absorption or use of the vitamin. People who eat a varied diet are unlikely to develop a severe primary vitamin deficiency, but may be consuming less than the recommended amounts; a national food and supplement survey conducted in the US over 2003-2006 reported that over 90% of individuals who did not consume vitamin supplements were found to have inadequate levels of some of the essential vitamins, notably vitamins D and E.
Well-researched human vitamin deficiencies involve thiamine (beriberi), niacin (pellagra
Pellagra is a disease caused by a lack of the vitamin niacin (vitamin B3). Symptoms include inflamed skin, diarrhea, dementia, and sores in the mouth. Areas of the skin exposed to either sunlight or friction are typically affected first. Over t ...
), vitamin C (scurvy), folate (neural tube defects) and vitamin D (rickets). In much of the developed world these deficiencies are rare due to an adequate supply of food and the addition of vitamins to common foods. In addition to these classical vitamin deficiency diseases, some evidence has also suggested links between vitamin deficiency and a number of different disorders.
Excess intake
Some vitamins have documented acute or chronic toxicity at larger intakes, which is referred to as hypertoxicity. The European Union and the governments of several countries have established Tolerable upper intake levels (ULs) for those vitamins which have documented toxicity (see table). The likelihood of consuming too much of any vitamin from food is remote, but excessive intake (vitamin poisoning
Hypervitaminosis is a condition of abnormally high storage levels of vitamins, which can lead to various symptoms as over excitement, irritability, or even toxicity. Specific medical names of the different conditions are derived from the given vit ...
) from dietary supplements does occur. In 2016, overdose exposure to all formulations of vitamins and multi-vitamin/mineral formulations was reported by 63,931 individuals to the American Association of Poison Control Centers
The American Association of Poison Control Centers (AAPCC) is a national nonprofit organization founded in 1958 that represents the nation's 55 poison centers. The AAPCC supports poison centers in their public health mission to prevent poisonin ...
with 72% of these exposures in children under the age of five. In the US, analysis of a national diet and supplement survey reported that about 7% of adult supplement users exceeded the UL for folate and 5% of those older than age 50 years exceeded the UL for vitamin A.
Effects of cooking
The USDA
The United States Department of Agriculture (USDA) is the federal executive department responsible for developing and executing federal laws related to farming, forestry, rural economic development, and food. It aims to meet the needs of com ...
has conducted extensive studies on the percentage losses of various nutrients from food types and cooking methods. Some vitamins may become more "bio-available" – that is, usable by the body – when foods are cooked. The table below shows whether various vitamins are susceptible to loss from heat—such as heat from boiling, steaming, frying, etc. The effect of cutting vegetables can be seen from exposure to air and light. Water-soluble vitamins such as B and C dissolve into the water when a vegetable is boiled, and are then lost when the water is discarded.
Recommended levels
In setting human nutrient guidelines, government organizations do not necessarily agree on amounts needed to avoid deficiency or maximum amounts to avoid the risk of toxicity.[Dietary Reference Intakes (DRIs)](_blank)
Food and Nutrition Board, Institute of Medicine, National Academies[Dietary Reference Intakes for Japanese (2010)](_blank)
National Institute of Health and Nutrition, Japan For example, for vitamin C, recommended intakes range from 40 mg/day in India to 155 mg/day for the European Union. The table below shows U.S. Estimated Average Requirements (EARs) and Recommended Dietary Allowances (RDAs) for vitamins, PRIs for the European Union (same concept as RDAs), followed by what three government organizations deem to be the safe upper intake. RDAs are set higher than EARs to cover people with higher than average needs. Adequate Intakes (AIs) are set when there is not sufficient information to establish EARs and RDAs. Governments are slow to revise information of this nature. For the U.S. values, with the exception of calcium and vitamin D, all of the data date to 1997–2004.[Dietary Reference Intakes: The Essential Guide to Nutrient Requirements, published by the Institute of Medicine's Food and Nutrition Board, currently available online at ]
All values are consumption per day:
EAR US Estimated Average Requirements.
RDA US Recommended Dietary Allowances; higher for adults than for children, and may be even higher for women who are pregnant or lactating.
AI US and EFSA Adequate Intake; AIs established when there is not sufficient information to set EARs and RDAs.
PRI Population Reference Intake is European Union equivalent of RDA; higher for adults than for children, and may be even higher for women who are pregnant or lactating. For Thiamin and Niacin the PRIs are expressed as amounts per MJ of calories consumed. MJ = megajoule = 239 food calories.
UL or Upper Limit Tolerable upper intake levels.
ND ULs have not been determined.
NE EARs have not been established.
Supplementation
In those who are otherwise healthy, there is little evidence that supplements have any benefits with respect to cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...
or heart disease
Cardiovascular disease (CVD) is a class of diseases that involve the heart or blood vessels. CVD includes coronary artery diseases (CAD) such as angina and myocardial infarction (commonly known as a heart attack). Other CVDs include stroke, hea ...
. Vitamin A and E supplements not only provide no health benefits for generally healthy individuals, but they may increase mortality, though the two large studies that support this conclusion included smokers for whom it was already known that beta-carotene supplements can be harmful. A 2018 meta-analysis found no evidence that intake of vitamin D or calcium for community-dwelling elderly people reduced bone fractures.
Europe has regulations that define limits of vitamin (and mineral) dosages for their safe use as dietary supplements. Most vitamins that are sold as dietary supplements are not supposed to exceed a maximum daily dosage referred to as the tolerable upper intake level
The Dietary Reference Intake (DRI) is a system of nutrition recommendations from the National Academy of Medicine (NAM) of the National Academies (United States). It was introduced in 1997 in order to broaden the existing guidelines known as Re ...
(UL or Upper Limit). Vitamin products above these regulatory limits are not considered supplements and should be registered as prescription or non-prescription (over-the-counter drug
Over-the-counter (OTC) drugs are medicines sold directly to a consumer without a requirement for a prescription from a healthcare professional, as opposed to prescription drugs
A prescription drug (also prescription medication or prescripti ...
s) due to their potential side effects. The European Union, United States and Japan establish ULs.
Dietary supplement
A dietary supplement is a manufactured product intended to supplement one's diet by taking a pill, capsule, tablet, powder, or liquid. A supplement can provide nutrients either extracted from food sources or that are synthetic in order ...
s often contain vitamins, but may also include other ingredients, such as minerals, herbs, and botanicals. Scientific evidence supports the benefits of dietary supplements for persons with certain health conditions.[Use and Safety of Dietary Supplements](_blank)
NIH office of Dietary Supplements. In some cases, vitamin supplements may have unwanted effects, especially if taken before surgery, with other dietary supplements or medicines, or if the person taking them has certain health conditions. They may also contain levels of vitamins many times higher, and in different forms, than one may ingest through food.
Governmental regulation
Most countries place dietary supplements in a special category under the general umbrella of ''foods'', not drugs. As a result, the manufacturer, and not the government, has the responsibility of ensuring that its dietary supplement products are safe before they are marketed. Regulation of supplements varies widely by country. In the United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
, a dietary supplement is defined under the Dietary Supplement Health and Education Act
The Dietary Supplement Health and Education Act of 1994 ("DSHEA"), is a 1994 statute of United States Federal legislation which defines and regulates dietary supplements. Under the act, supplements are regulated by the FDA for Good Manufacturing ...
of 1994. There is no FDA approval process for dietary supplements, and no requirement that manufacturers prove the safety or efficacy of supplements introduced before 1994. The Food and Drug Administration
The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respon ...
must rely on its Adverse Event Reporting System to monitor adverse events that occur with supplements.
In 2007, the US Code of Federal Regulations
In the law of the United States, the ''Code of Federal Regulations'' (''CFR'') is the codification of the general and permanent regulations promulgated by the executive departments and agencies of the federal government of the United States. ...
(CFR) Title 21, part III took effect, regulating Good Manufacturing Practices (GMPs) in the manufacturing, packaging, labeling, or holding operations for dietary supplements. Even though product registration is not required, these regulations mandate production and quality control standards (including testing for identity, purity and adulterations) for dietary supplements. In the European Union, the Food Supplements Directive
A dietary supplement is a manufactured product intended to supplement one's diet by taking a pill, capsule, tablet, powder, or liquid. A supplement can provide nutrients either extracted from food sources or that are synthetic in orde ...
requires that only those supplements that have been proven safe can be sold without a prescription. For most vitamins, pharmacopoeial standards have been established. In the United States, the United States Pharmacopeia
The ''United States Pharmacopeia'' (''USP'') is a pharmacopeia (compendium of drug information) for the United States published annually by the United States Pharmacopeial Convention (usually also called the USP), a nonprofit organization that ...
(USP) sets standards for the most commonly used vitamins and preparations thereof. Likewise, monographs of the European Pharmacopoeia
The ''European Pharmacopoeia'' (''Pharmacopoeia Europaea'', ''Ph. Eur.'') is a major regional pharmacopoeia which provides common quality standards throughout the pharmaceutical industry in Europe to control the quality of medicines, and the su ...
(Ph.Eur.) regulate aspects of identity and purity for vitamins on the European market.
Naming
The reason that the set of vitamins skips directly from E to K is that the vitamins corresponding to letters F–J were either reclassified over time, discarded as false leads, or renamed because of their relationship to vitamin B, which became a complex of vitamins.
The Danish-speaking scientists who isolated and described vitamin K (in addition to naming it as such) did so because the vitamin is intimately involved in the coagulation of blood following wounding (from the Danish
Danish may refer to:
* Something of, from, or related to the country of Denmark
People
* A national or citizen of Denmark, also called a "Dane," see Demographics of Denmark
* Culture of Denmark
* Danish people or Danes, people with a Danish a ...
word ''Koagulation''). At the time, most (but not all) of the letters from F through to J were already designated, so the use of the letter K was considered quite reasonable. The table ''Nomenclature of reclassified vitamins'' lists chemicals that had previously been classified as vitamins, as well as the earlier names of vitamins that later became part of the B-complex.
The missing B vitamins were reclassified or determined not to be vitamins. For example, B9 is folic acid
Folate, also known as vitamin B9 and folacin, is one of the B vitamins. Manufactured folic acid, which is converted into folate by the body, is used as a dietary supplement and in food fortification as it is more stable during processing and ...
and five of the folates are in the range B11 through B16. Others, such as PABA (formerly B10), are biologically inactive, toxic, or with unclassifiable effects in humans, or not generally recognised as vitamins by science,Vitamins: What Vitamins Do I Need?
Medical News Today. Retrieved on 2015-11-30. such as the highest-numbered, which some naturopath practitioners call B21 and B22. There are also nine lettered B complex vitamins (e.g., Bm). There are other D vitamins now recognised as other substances, which some sources of the same type number up to D7. The controversial cancer treatment laetrile
Amygdalin (from Ancient Greek: ' "almond") is a naturally occurring chemical compound found in many plants, most notably in the seeds (kernels) of apricots, bitter almonds, apples, peaches, cherries, and plums.
Amygdalin is classified as a ...
was at one point lettered as vitamin B17. There appears to be no consensus on any vitamins Q, R, T, V, W, X, Y or Z, nor are there substances officially designated as vitamins N or I, although the latter may have been another form of one of the other vitamins or a known and named nutrient of another type.
See also
*Vitamin deficiency
Vitamin deficiency is the condition of a long-term lack of a vitamin. When caused by not enough vitamin intake it is classified as a ''primary deficiency'', whereas when due to an underlying disorder such as malabsorption it is called a ''seconda ...
*Hypervitaminosis
Hypervitaminosis is a condition of abnormally high storage levels of vitamins, which can lead to various symptoms as over excitement, irritability, or even toxicity. Specific medical names of the different conditions are derived from the given vit ...
*Human nutrition
Human nutrition deals with the provision of essential nutrients in food that are necessary to support human life and good health. Poor nutrition is a chronic problem often linked to poverty, food security, or a poor understanding of nutritiona ...
References
External links
USDA RDA chart in PDF format
* ttp://dietary-supplements.info.nih.gov/Health_Information/Vitamin_and_Mineral_Supplement_Fact_Sheets.aspx NIH Office of Dietary Supplements: Fact Sheets
{{Authority control
Essential nutrients
Nutrition