B vitamins/ja: Difference between revisions

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==Deficiencies==

{{See also|Vitamin deficiency#Water-soluble vitamins}}

!Vitamin!! Name !! Deficiency effects

  ! Vitamin&nbsp;B₁  

| [[Thiamine]] || [[Thiamine deficiency]] causes [[thiamine deficiency#Beriberi|beriberi]]. Symptoms of this disease of the [[nervous system]] include weight loss, emotional disturbances, [[Wernicke encephalopathy]] (impaired sensory perception), weakness and pain in the limbs, periods of [[Heart arrhythmia|irregular heartbeat]], and [[edema]] (swelling of bodily tissues). [[Heart failure]] and [[death]] may occur in advanced cases. Chronic thiamine deficiency can also cause [[alcoholic Korsakoff syndrome]], an irreversible [[dementia]] characterized by [[amnesia]] and compensatory [[confabulation]].

  ! Vitamin&nbsp;B₂  

| [[Riboflavin]] || [[Riboflavin deficiency]] can cause [[ariboflavinosis]], which may result in [[Angular cheilitis|cheilosis]] (cracks in the lips), high sensitivity to sunlight, [[angular cheilitis]], [[glossitis]] (inflammation of the tongue), [[seborrheic dermatitis]] or pseudo-[[syphilis]] (particularly affecting the [[scrotum]] or [[labia majora]] and the [[nasolabial folds|mouth]]), [[sore throat|pharyngitis]] (sore throat), [[hyperemia]], and edema of the [[Pharynx|pharyngeal]] and [[Wiktionary:oral|oral]] [[mucous membrane|mucosa]].

  ! Vitamin&nbsp;B₃  

| [[Niacin (nutrient)|Niacin]] || [[Niacin deficiency]], along with a deficiency of [[tryptophan]], causes [[pellagra]]. Symptoms include aggression, [[dermatitis]], [[insomnia]], [[weakness]], mental confusion, and [[diarrhea]]. In advanced cases, pellagra may lead to [[dementia]] and death (the 3(+1) D's: dermatitis, diarrhea, dementia, and death).

  ! Vitamin&nbsp;B₅  

| [[Pantothenic acid]] || [[Pantothenic acid deficiency]] can result in [[acne]] and [[paresthesia]], although it is uncommon.

  ! Vitamin&nbsp;B₆

| [[Pyridoxine]], [[pyridoxal]], [[pyridoxamine]] || [[Vitamin B6#Deficiency|Vitamin B₆ deficiency]] causes seborrhoeic dermatitis-like eruptions, pink eye and neurological symptoms (e.g. [[epilepsy]]).

  ! Vitamin&nbsp;B₇

| [[Biotin]] || [[Biotin deficiency]] does not typically cause symptoms in adults, other than cosmetic issues such as decreased hair and nail growth, but may lead to impaired growth and neurological disorders in infants. [[Multiple carboxylase deficiency]], an inborn error of metabolism, can lead to biotin deficiency even when dietary biotin intake is normal.

  ! Folate

| [[Folic acid]] || [[Folic acid deficiency]] results in a [[macrocytic anemia]], and elevated levels of [[homocysteine]]. Deficiency in pregnant women can lead to birth defects, particularly [[neural tube defect]]s such as [[spina bifida]] and [[anencephaly]].

  !Vitamin&nbsp;B₁₂  

| [[Cobalamin]]s || [[Vitamin B12 deficiency|Vitamin B₁₂ deficiency]] results in a [[megaloblastic anemia|macrocytic anemia]], elevated [[methylmalonic acid]] and [[homocysteine]], [[peripheral neuropathy]], sense loss, change in mobility, memory loss and other cognitive deficits. It is most likely to occur among elderly people, as absorption through the gut declines with age; the autoimmune disease [[pernicious anemia]] is another common cause. It can also cause symptoms of [[mania]] and [[psychosis]]. Untreated, it is possible to cause irreversible damage to the brain and nerve system — In rare extreme cases, paralysis can result.

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==Side effects==

! Vitamin !! Tolerable Upper Intake Level (UL) !! Harmful effects

  ! Vitamin&nbsp;B₁

| None || No known toxicity from oral intake. There are some reports of [[anaphylaxis]] caused by high-dose thiamin injections into the vein or muscle. However, the doses were greater than the quantity humans can physically absorb from oral intake.

  ! Vitamin&nbsp;B₂  

| None || No evidence of toxicity based on limited human and animal studies. The only evidence of adverse effects associated with riboflavin comes from ''[[in vitro]]'' studies showing the production of [[reactive oxygen species]] ([[free radicals]]) when riboflavin was exposed to intense visible and UV light.

  !Vitamin&nbsp;B₃  

| US UL = 35&nbsp;mg as a dietary supplement || Intake of 3000&nbsp;mg/day of nicotinamide and 1500&nbsp;mg/day of nicotinic acid are associated with nausea, vomiting, and signs and symptoms of liver toxicity. Other effects may include glucose intolerance, and (reversible) ocular effects. Additionally, the nicotinic acid form may cause vasodilatory effects, also known as [[Flushing (physiology)|flushing]], including redness of the skin, often accompanied by an itching, tingling, or mild burning sensation, which is also often accompanied by [[pruritus]], headaches, and increased intracranial blood flow, and occasionally accompanied by pain. Medical practitioners prescribe recommended doses up to 2000&nbsp;mg per day of niacin in either immediate-release or slow-release formats, to lower plasma triglycerides and low-density lipiprotein cholesterol.

  ! Vitamin&nbsp;B₅  

| None || No toxicity known.

  ! Vitamin&nbsp;B₆  

| US&nbsp;UL&nbsp;=&nbsp;100&nbsp;mg/day; EU&nbsp;UL&nbsp;=&nbsp;25&nbsp;mg/day || See [[Megavitamin-B6 syndrome|Megavitamin-B₆ syndrome]] for more information.

  ! Vitamin&nbsp;B₇  

| None || No toxicity known.

  ! Folate

| 1&nbsp;mg/day || Masks B₁₂ deficiency, which can lead to permanent [[neurological]] damage.

  ! Vitamin&nbsp;B₁₂  

| None established || Skin and spinal lesions. Acne-like rash [causality is not conclusively established].

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==Discovery==

! Vitamin!! Name !! Discoverer!!Date!!Notes

! rowspan="2" |Vitamin&nbsp;B₁  

| rowspan="2" |[[Thiamine]] || [[Umetaro Suzuki]]||1910||Failed to gain publicity.

| [[Casimir Funk]] || 1912||

! Vitamin&nbsp;B₂

| [[Riboflavin]] || D.T Smith and E.G Hendrick

| 1926|| [[Max Tishler]] invented methods for [[chemical synthesis|synthesizing]] it.

! Vitamin&nbsp;B₃

| [[Niacin (substance)|Niacin]] || [[Conrad Elvehjem]]|| 1937||

! Vitamin&nbsp;B₅

| [[Pantothenic acid]] || [[Roger J. Williams]]||1933||

! Vitamin&nbsp;B₆  

| [[Pyridoxine]] etc. || [[Paul Gyorgy]]||1934||

! Vitamin&nbsp;B₇

| [[Biotin]] || colspan=3|Research by multiple independent groups in the early 1900s; credits for discovery include [[Margaret Averil Boas]] (1927), and [[Dean Burk]].

! Vitamin&nbsp;B₉  

| [[Folic acid]] || [[Lucy Wills]]||1933||

!Vitamin&nbsp;B₁₂

| [[Cobalamin]]s || colspan=3|[[Vitamin B12#History|Five people]] have been awarded [[Nobel Prize]]s for direct and indirect studies of vitamin B₁₂: [[George Whipple]], [[George Minot]] and [[William P. Murphy|William Murphy]] (1934), [[Alexander R. Todd]] (1957), and [[Dorothy Hodgkin]] (1964).

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==Related compounds==

Many of the following substances have been referred to as vitamins as they were once believed to be vitamins. They are no longer considered as such, and the numbers that were assigned to them now form the "gaps" in the true series of B-complex vitamins described above (for example, there is no vitamin B₄). Some of them, though not essential to humans, are essential in the diets of other organisms; others have no known nutritional value and may even be toxic under certain conditions.

* '''Vitamin B₄''': can refer to the distinct chemicals [[choline]], [[adenine]], or [[carnitine]].

** Choline is [[biosynthesis|synthesized]] by the human body, but not sufficiently to maintain good health, and is now considered an essential dietary nutrient.

** Adenine is a [[nucleobase]] synthesized by the human body.

** Carnitine is an essential dietary nutrient for certain worms, but not for humans.

* '''Vitamin B₈''': [[adenosine monophosphate]] (AMP), also known as adenylic acid. Vitamin B₈ may also refer to [[inositol]].

* '''Vitamin B₁₀''': [[4-Aminobenzoic acid|''para''-aminobenzoic acid]] (pABA or PABA), a chemical component of the folate molecule produced by plants and bacteria, and found in many foods. It is best known as a [[ultraviolet light|UV]]-blocking [[sunscreen]] applied to the skin, and is sometimes taken orally for certain medical conditions.

* '''Vitamin B₁₁''': pteroylheptaglutamic acid (PHGA; chick growth factor). Vitamin Bc-conjugate was also found to be identical to PHGA. Derivative of [[folate]] ("pteroylmonoglutamic acid" in this nomenclature).

* '''Vitamin B₁₃''': [[orotic acid]].

* '''Vitamin B₁₄''': cell proliferant, anti-[[anemia]], rat growth factor, and antitumor [[pterin]] phosphate, named by Earl R. Norris. Isolated from human urine at 0.33ppm (later in blood), but later abandoned by him as further evidence did not confirm this. He also claimed this was not [[xanthopterin]].

* '''Vitamin B₁₅''': [[pangamic acid]], also known as pangamate. Promoted in various forms as a dietary supplement and drug; considered unsafe and subject to seizure by the US [[Food and Drug Administration]].

* '''Vitamin B₁₆''': [[dimethylglycine]] (DMG) is synthesized by the human body from choline.

* '''Vitamin B₁₇''': pseudoscientific name for the poisonous compound [[amygdalin]], also known as the equally pseudoscientific name "nitrilosides" despite the fact that it is a single compound. Amygdalin can be found in various plants, but is most commonly extracted from apricot pits and other similar fruit kernels. Amygdalin is hydrolyzed by various intestinal enzymes to form, among other things, hydrogen cyanide, which is toxic to human beings when exposed to a high enough dosage. Some proponents claim that amygdalin is effective in cancer treatment and prevention, despite its toxicity and a lack of scientific evidence.

* '''Vitamin B₂₀''': <small>L</small>-carnitine.

* '''Vitamin B_f''': carnitine.

* '''Vitamin B_m''': [[inositol|''myo''-inositol]], also called "mouse antialopaecia factor".

* '''Vitamin B_p''': "antiperosis factor", which prevents [[perosis]], a leg disorder, in [[chicken|chicks]]; can be replaced by choline and manganese salts.

* '''Vitamin B_T''': carnitine.

* '''Vitamin B_v''': a type of B₆ other than pyridoxine.

* '''Vitamin B_W''': a type of biotin other than d-biotin.

* '''Vitamin B_x''': an alternative name for both pABA (see vitamin B₁₀) and [[pantothenic acid]].

{{Vitamins}}

{{Nutritional pathology}}