BIOTIN

Biotin (also known as vitamin B7 or vitamin H) 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, borrowed from the German Biotin, derives from the Ancient Greek word βίοτος (bíotos; 'life') and the suffix "-in" (a suffix used in chemistry usually to indicate 'forming').
Biotin appears as a white crystalline solid that looks like needles.

CAS Number: 58-85-5
EC Number: 200-399-3
IUPAC Name: 5-[(3aS,4S,6aR)-2-Oxohexahydro-1H-thieno[3,4-d]imidazol-4-yl]pentanoic acid
Chemical formula: C10H16N2O3S

Other names: biotin, d-biotin, 58-85-5, vitamin H, Vitamin B7, Bioepiderm, coenzyme R, Bios II, Factor S, D(+)-Biotin, Biodermatin, D-(+)-Biotin, (+)-Biotin, Biotine, Biotinum, Injacom H, Biotina, Meribin, Lutavit H2, Ritatin, CCRIS 3932, HSDB 346, 3H-Biotin, MFCD00005541, NSC 63865, 5-((3aS,4S,6aR)-2-oxohexahydro-1H-thieno[3,4-d]imidazol-4-yl)pentanoic acid, cis-Hexahydro-2-oxo-1H-thieno(3,4)imidazole-4-valeric acid, cis-Tetrahydro-2-oxothieno(3,4-d)imidazoline-4-valeric acid, AI3-51198, 1swk, 1swn, 1swr, EINECS 200-399-3, Rovimix H 2, UNII-6SO6U10H04, 5-[(3aS,4S,6aR)-2-oxo-hexahydro-1H-thieno[3,4-d]imidazolidin-4-yl]pentanoic acid, CHEBI:15956, 6SO6U10H04, 5-[(3aS,4S,6aR)-2-oxohexahydro-1H-thieno[3,4-d]imidazol-4-yl]pentanoic acid, 5-[(3aS,4S,6aR)-2-oxo-1,3,3a,4,6,6a-hexahydrothieno[3,4-d]imidazol-4-yl]pentanoic acid, Medebiotin, NSC-63865, cis-(+)-Tetrahydro-2-oxothieno[3,4]imidazoline-4-valeric acid, (+)-cis-Hexahydro-2-oxo-1H-thieno[3,4]imidazole-4-valeric acid, MD-1003, 1H-thieno[3,4-d]imidazole-4-pentanoic acid, hexahydro-2-oxo-, (3aS,4S,6aR)-, 1H-Thieno(3,4-d)imidazole-4-pentanoic acid, hexahydro-2-oxo-, (3aS-(3aalpha,4beta,6aalpha))-, DTXCID102679, DTXSID7022679, 2'-Keto-3,4-imidazolido-2-tetrahydrothiophene-N-valeric acid, (3aS,4S,6aR)-Hexahydro-2-oxo-1H-thieno(3,4-d)imidazole-4-valeric acid, (3aS,4S,6aR)-Hexahydro-2-oxo-1H-thieno[3,4-d]imidazole-4-valeric acid, Hexahydro-2-oxo-1H-thieno(3,4-d)imidazole-4-pentanoic acid, (3aS-(3aalpha,4beta,6aalpha))-, beta-Biotin, Hexahydro-2-oxo-1H-thieno(3,4-d)imidazole-4-pentanoic acid, 1H-Thieno(3,4-d)imidazole-4-pentanoic acid, hexahydro-2-oxo-, (3aS,4S,6aR)-, 5-((3AS,4S,6aR)-rel-2-oxohexahydro-1H-thieno[3,4-d]imidazol-4-yl)pentanoic acid, Bios H, SMR000112255, D(+)Biotin, 22377-59-9, Biotitum, hexahydro-2-oxo-1H-thieno[3,4-d]imidazole-4-pentanoic acid, NSC63865, delta-Biotin, Amerix Biotin, Biotin Drops, Hairq-plus, Vitamin-h, Tk-nax, 1avd, 1ndj, 1stp, 1swg, 1swp, 2avi, 4bcs, 4ggz, 4jnj, CAS-58-85-5, NCGC00094984-04, 1H-Thieno[3,4-d]imidazole-4-pentanoic acid, hexahydro-2-oxo-, [3as-(3aalpha,4beta,6aalpha)]-, Biotin111In, delta-(+)-Biotin, SUBIR, Biotin Drops2081, Biotin (8CI), 1df8, 1n9m, 2gh7, 3t2w, 4bj8, Prestwick0_000418, Prestwick1_000418, Prestwick2_000418, Prestwick3_000418, cid_253, SPAI-SONSPROLAC-VIT, BDBM12, bmse000227, CHEMBL857, Probes2_000006, SCHEMBL8763, BSPBio_000376, MLS001066402, MLS001074888, MLS001331736, MLS001333089, SPBio_002315, BPBio1_000414, cid_171548, GTPL4787, A11HA05, AMF0005, 1n43, 2f01, CIS-TETRAHYDRO-2-OXOTHIENO, HMS1569C18, HMS2096C18, HMS2271O06, HMS3713C18, HY-B0511, Tox21_113050, Tox21_302161, AC8089, s3130, AKOS001287669, Tox21_113050_1, CCG-220418, CIS-HEXAHYDRO-2-OXO-1H-THIENO, DB00121, 1H-Thieno(3,4-d)imidazole-4-pentanoic acid, hexahydro-2-oxo-, (3aS-(3aalpha,4b,6aalpha))-, NCGC00179580-01, NCGC00179580-02, NCGC00179580-04, NCGC00179580-08, NCGC00255377-01, 56846-45-8, AC-19998, BP-20441, AB00374191, B0463, NS00126825, EN300-54173, C00120, D00029, M02926, AB00374191-08, AB00374191_11, A929752, Q181354, SR-01000765521, Q-200929, SR-01000765521-2, BRD-K89210380-001-03-8, BRD-K89210380-001-13-7, 6AE43AA3-BC3D-4C49-9DB9-5913A2401EB6, Biotin, European Pharmacopoeia (EP) Reference Standard, F2173-0855, Hexahydro-2-oxo-1H-thieno(3,4-d)imidazole-4-pentanoate, Z210803762, cis-(+)-Tetrahydro-2-oxothieno[3,4]imidazoline-4-valerate, (+)-cis-Hexahydro-2-oxo-1H-thieno[3,4]imidazole-4-valerate, 5-(2-oxohexahydro-1H-thieno[3,4-d]imidazol-4-yl)pentanoate, Daunorubicin hydrochloride, Antibiotic for Culture Media Use Only, (3aS,4S,6aR)-Hexahydro-2-oxo-1H-thieno[3,4-d]imidazole-4-valerate, Biotin, Pharmaceutical Secondary Standard; Certified Reference Material, 1H-Thieno[3,4-d]imidazole-4-pentanoic acid, hexahydro-2-oxo-, (3aS,4S,6aR)- (9CI), 5-((3aR,6S,6aS)-2-Oxo-hexahydro-thieno[3,4-d]imidazol-6-yl)-pentanoic acid, 5-[(3aR,6S,6aS)-2-oxo-1,3,3a,4,6,6a-hexahydrothieno[3,4-d]imidazol-6-yl]pentanoic acid, hexahydro-2-oxo-[3aS-(3aa,4b,6aa)]-1H-Thieno[3,4-d]imidazole-4-pentanoate, hexahydro-2-oxo-[3aS-(3aa,4b,6aa)]-1H-Thieno[3,4-d]imidazole-4-pentanoic acid, hexahydro-2-oxo-[3as-(3alpha,4beta,6alpha)]-1H-Thieno[3,4-d]imidazole-4-pentanoate, hexahydro-2-oxo-[3as-(3alpha,4beta,6alpha)]-1H-Thieno[3,4-d]imidazole-4-pentanoic acid

Chemical description
Biotin is classified as a heterocyclic compound, with a sulfur-containing tetrahydrothiophene ring fused to a ureido group. A C5-carboxylic acid side chain is appended to the former ring. The ureido ring, containing the −N−CO−N− group, serves as the carbon dioxide carrier in carboxylation reactions.

Biotin is a coenzyme for five carboxylase enzymes, which are involved in the catabolism of amino acids and fatty acids, synthesis of fatty acids, and gluconeogenesis.
Biotinylation of histone proteins in nuclear chromatin plays a role in chromatin stability and gene expression.

Dietary recommendations
The US National Academy of Medicine updated Dietary Reference Intakes for many vitamins in 1998. At that time there was insufficient information to establish estimated average requirement or recommended dietary allowance, terms that exist for most vitamins. In instances such as this, the academy sets adequate intakes (AIs) with the understanding that at some later date, when the physiological effects of biotin are better understood, AIs will be replaced by more exact information.

The biotin AIs for both males and females are: 5 μg/day of biotin for 0-to-6-month-olds, 6 μg/day of biotin for 7-to-12-month-olds, 8 μg/day of biotin for 1-to-3-year-olds, 12 μg/day of biotin for 4-to-8-year-olds, 20 μg/day of biotin for 9-to-13-year-olds, 25 μg/day of biotin for 14-to-18-year-olds, and 30 μg/day of biotin for those 19 years old and older.

The biotin AIs for females who are either pregnant or lactating, respectively, are: 30 μg/day of biotin for pregnant females 14-to-50-years old and 35 μg/day of biotin for lactating females 14-to-50-years old.
Australia and New Zealand set AIs similar to the US.

Safety
The US National Academy of Medicine estimates upper limits for vitamins and minerals when evidence for a true limit is sufficient. For biotin, however, there is no upper limit because adverse effects of high biotin intake have not been determined.
The EFSA also reviewed safety and reached the same conclusion as in the United States.

Labeling regulations
For US food and dietary supplement labeling purposes the amount in a serving is expressed as a percent of daily value.
For biotin labeling purposes 100% of the daily value was 300 μg/day, but as of May 27, 2016, it was revised to 30 μg/day to bring it into an agreement with the adequate intake.

Compliance with the updated labeling regulations was required by January 1, 2020, for manufacturers with US$10 million or more in annual food sales, and by January 1, 2021, for manufacturers with lower volume food sales.
A table of the old and new adult daily values is provided at Reference Daily Intake.

Physiology
Biotin is a water-soluble B vitamin.
Consumption of large amounts as a dietary supplement results in absorption, followed by excretion into urine as biotin. Consumption of biotin as part of a normal diet results in urinary excretion of biotin and biotin metabolites.

Absorption
Biotin in food is bound to proteins. Digestive enzymes reduce the proteins to biotin-bound peptides.
The intestinal enzyme biotinidase, found in pancreatic secretions and in the brush border membranes of all three parts of the small intestine, frees biotin, which is then absorbed from the small intestine.
When consumed as a biotin dietary supplement, absorption is nonsaturable, meaning that even very high amounts are absorbed effectively. Transport across the jejunum is faster than across the ileum.

The large intestine microbiota synthesize amounts of biotin estimated to be similar to the amount taken in the diet, and a significant portion of this biotin exists in the free (protein-unbound) form and, thus, is available for absorption.
How much is absorbed in humans is unknown, although a review did report that human epithelial cells of the colon in vitro demonstrated an ability to uptake biotin.

Once absorbed, sodium-dependent multivitamin transporter (SMVT) mediates biotin uptake into the liver.
SMVT also binds pantothenic acid, so high intakes of either of these vitamins can interfere with transport of the other.

Metabolism and excretion
Biotin catabolism occurs via two pathways.
In one, the valeric acid sidechain is cleaved, resulting in bisnorbiotin.
In the other pathway, the sulfur is oxidized, resulting in biotin sulfoxide.
Urine content is proportionally about half biotin, plus bisnorbiotin, biotin sulfoxide, and small amounts of other metabolites.

Factors that affect biotin requirements
Chronic alcohol use is associated with a significant reduction in plasma biotin.
Intestinal biotin uptake also appears to be sensitive to the effect of the anti-epilepsy drugs carbamazepine and primidone. Relatively low levels of biotin have also been reported in the urine or plasma of patients who have had a partial gastrectomy or have other causes of achlorhydria, as well as burn patients, elderly individuals, and athletes.

Pregnancy and lactation may be associated with an increased demand for biotin.
In pregnancy, this may be due to a possible acceleration of biotin catabolism, whereas, in lactation, the higher demand has yet to be elucidated.
Recent studies have shown marginal biotin deficiency can be present in human gestation, as evidenced by increased urinary excretion of 3-hydroxyisovaleric acid, decreased urinary excretion of biotin and bisnorbiotin, and decreased plasma concentration of biotin.

Biosynthesis
Biotin, synthesized in plants, is essential to plant growth and development.
Bacteria also synthesize biotin, and it is thought that bacteria resident in the large intestine may synthesize biotin that is absorbed and utilized by the host organism.

Biosynthesis starts from two precursors, alanine and pimeloyl-CoA.
These form 7-keto-8-aminopelargonic acid (KAPA).
KAPA is transported from plant peroxisomes to mitochondria where it is converted to 7,8-diaminopelargonic acid (DAPA) with the help of the enzyme, BioA.

The enzyme dethiobiotin synthetase catalyzes the formation of the ureido ring via a DAPA carbamate activated with ATP, creating dethiobiotin with the help of the enzyme, BioD, which is then converted into biotin which is catalyzed by BioB.
The last step is catalyzed by biotin synthase, a radical SAM enzyme.
The sulfur is donated by an unusual [2Fe-2S] ferredoxin.
Depending on the species of bacteria, Biotin can be synthesized via multiple pathways.

Cofactor biochemistry
The enzyme holocarboxylase synthetase covalently attaches biotin to five human carboxylase enzymes:

Acetyl-CoA carboxylase alpha (ACC1)
Acetyl-CoA carboxylase beta (ACC2)
Pyruvate carboxylase (PC)
Methylcrotonyl-CoA carboxylase (MCC)
Propionyl-CoA carboxylase (PCC)

For the first two, biotin serves as a cofactor responsible for transfer of bicarbonate to acetyl-CoA, converting it to malonyl-CoA for fatty acid synthesis. PC participates in gluconeogenesis.
MCC catalyzes a step in leucine metabolism. PCC catalyzes a step in the metabolism of propionyl-CoA.
Metabolic degradation of the biotinylated carboxylases leads to the formation of biocytin.
This compound is further degraded by biotinidase to release biotin, which is then reutilized by holocarboxylase synthetase.

Biotinylation of histone proteins in nuclear chromatin is a posttranslational modification that plays a role in chromatin stability and gene expression.

Deficiency
Main article: Biotin deficiency
Primary biotin deficiency, meaning deficiency as a consequence of too little biotin in the diet, is rare, because biotin is contained in so many foods.
Subclinical deficiency can cause mild symptoms, such as hair thinning, brittle fingernails, or skin rash, typically on the face.

Aside from inadequate dietary intake (rare), deficiency of biotin can be caused by a genetic disorder that affects biotin metabolism.
The most common among these is biotinidase deficiency. Low activity of this enzyme causes a failure to recycle biotin from biocytin. Rarer are carboxylase and biotin transporter deficiences.

Neonatal screening for biotinidase deficiency started in the United States in 1984, with many countries now also testing for this genetic disorder at birth. Treatment is lifelong dietary supplement with biotin.
If biotinidase deficiency goes untreated, it can be fatal.

Diagnosis
Low serum and urine biotin are not sensitive indicators of inadequate biotin intake.
However, serum testing can be useful for confirmation of consumption of biotin-containing dietary supplements, and whether a period of refraining from supplement use is long enough to eliminate the potential for interfering with drug tests.

Indirect measures depend on the biotin requirement for carboxylases.
3-Methylcrotonyl-CoA is an intermediate step in the catabolism of the amino acid leucine.
In the absence of biotin, the pathway diverts to 3-hydroxyisovaleric acid.
Urinary excretion of this compound is an early and sensitive indicator of biotin deficiency.

Deficiency as a result of metabolic disorders
Biotinidase deficiency is a deficiency of the enzyme that recycles biotin, the consequence of an inherited genetic mutation.
Biotinidase catalyzes the cleavage of biotin from biocytin and biotinyl-peptides (the proteolytic degradation products of each holocarboxylase) and thereby recycles biotin.

It is also important in freeing biotin from dietary protein-bound biotin.
Neonatal screening for biotinidase deficiency started in the United States in 1984, which as of 2017 was reported as required in more than 30 countries.

Profound biotinidase deficiency, defined as less than 10% of normal serum enzyme activity, which has been reported as 7.1 nmol/min/mL, has an incidence of 1 in 40,000 to 1 in 60,000, but with rates as high as 1 in 10,000 in countries with high incidence of consanguineous marriages (second cousin or closer).
Partial biotinidase deficiency is defined as 10% to 30% of normal serum activity.
Incidence data stems from government mandated newborn screening.

For profound deficiency, treatment is oral dosing with 5 to 20 mg per day.
Seizures are reported as resolving in hours to days, with other symptoms resolving within weeks.
Treatment of partial biotinidase deficiency is also recommended even though some untreated people never manifest symptoms.
Lifelong treatment with supplemental biotin is recommended for both profound and partial biotinidase deficiency.

Inherited metabolic disorders characterized by deficient activities of biotin-dependent carboxylases are termed multiple carboxylase deficiency.
These include deficiencies in the enzymes holocarboxylase synthetase.
Holocarboxylase synthetase deficiency prevents the body's cells from using biotin effectively and thus interferes with multiple carboxylase reactions.
There can also be a genetic defect affecting the sodium-dependent multivitamin transporter protein.

Biochemical and clinical manifestations of any of these metabolic disorders can include ketolactic acidosis, organic aciduria, hyperammonemia, rash, hypotonia, seizures, developmental delay, alopecia and coma.

Use in biotechnology
Chemically modified versions of biotin are widely used throughout the biotechnology industry to isolate proteins and non-protein compounds for biochemical assays.
Because egg-derived avidin binds strongly to biotin with a dissociation constant Kd ≈ 10−15 M, biotinylated compounds of interest can be isolated from a sample by exploiting this highly stable interaction.
First, the chemically modified biotin reagents are bound to the targeted compounds in a solution via a process called biotinylation.
The choice of which chemical modification to use is responsible for the biotin reagent binding to a specific protein.

Second, the sample is incubated with avidin bound to beads, then rinsed, removing all unbound proteins, while leaving only the biotinylated protein bound to avidin.
Last, the biotinylated protein can be eluted from the beads with excess free biotin.
The process can also utilize bacteria-derived streptavidin bound to beads, but because it has a higher dissociation constant than avidin, very harsh conditions are needed to elute the biotinylated protein from the beads, which often will denature the protein of interest.

Interference with medical laboratory results
When people are ingesting high levels of biotin in dietary supplements, a consequence can be clinically significant interference with diagnostic blood tests that use biotin-streptavidin technology.
This methodology is commonly used to measure levels of hormones such as thyroid hormones, and other analytes such as 25-hydroxyvitamin D. Biotin interference can produce both falsely normal and falsely abnormal results.

In the US, biotin as a non-prescription dietary supplement is sold in amounts of 1 to 10 mg per serving, with claims for supporting hair and nail health, and as 300 mg per day as a possibly effective treatment for multiple sclerosis.
Overconsumption of 5 mg/day or higher causes elevated concentration in plasma that interferes with biotin-streptavidin immunoassays in an unpredictable manner.
Healthcare professionals are advised to instruct patients to stop taking biotin supplements for 48 h or even up to weeks before the test, depending on the specific test, dose, and frequency of biotin uptake.
Guidance for laboratory staff is proposed to detect and manage biotin interference.

History
In 1916, W. G. Bateman observed that a diet high in raw egg whites caused toxic symptoms in dogs, cats, rabbits, and humans.
By 1927, scientists such as Margarete Boas and Helen Parsons had performed experiments demonstrating the symptoms associated with "egg-white injury".
They had found that rats fed large amounts of egg-white as their only protein source exhibited neurological dysfunction, hair loss, dermatitis, and eventually, death.

In 1936, Fritz Kögl and Benno Tönnis documented isolating a yeast growth factor in a journal article titled "Darstellung von krystallisiertem biotin aus eigelb." (Representation of crystallized biotin from egg yolk).
The name biotin derives from the Greek word bios ('to live') and the suffix "-in" (a general chemical suffix used in organic chemistry).

Other research groups, working independently, had isolated the same compound under different names. Hungarian scientist Paul Gyorgy began investigating the factor responsible for egg-white injury in 1933 and in 1939, was successful identifying what he called "Vitamin H" (the H represents Haar und Haut, German for 'hair and skin').

Further chemical characterization of vitamin H revealed that it was water-soluble and present in high amounts in the liver.
After experiments performed with yeast and Rhizobium trifolii, West and Wilson isolated a compound they called co-enzyme R.
By 1940, it was recognized that all three compounds were identical and were collectively given the name: biotin.

Gyorgy continued his work on biotin and in 1941 published a paper demonstrating that egg-white injury was caused by the binding of biotin by avidin.
Unlike for many vitamins, there is insufficient information to establish a recommended dietary allowance, so dietary guidelines identify an "adequate intake" based on best available science with the understanding that at some later date this will be replaced by more exact information.

Using E. coli, a biosynthesis pathway was proposed by Rolfe and Eisenberg in 1968.
The initial step was described as a condensation of pimelyl-CoA and alanine to form 7-oxo-8-aminopelargonic acid.
From there, they described three-step process, the last being introducing a sulfur atom to form the tetrahydrothiophene ring.

Research
Multiple sclerosis
High-dose biotin (300 mg/day = 10,000 times adequate intake) has been used in clinical trials for treatment of multiple sclerosis, a demyelinating autoimmune disease.
The hypothesis is that biotin may promote remyelination of the myelin sheath of nerve cells, slowing or even reversing neurodegeneration.

The proposed mechanisms are that biotin activates acetyl-coA carboxylase, which is a key rate-limiting enzyme during the synthesis of myelin, and by reducing axonal hypoxia through enhanced energy production.
Clinical trial results are mixed; a 2019 review concluded that a further investigation of the association between multiple sclerosis symptoms and biotin should be undertaken, whereas two 2020 reviews of a larger number of clinical trials reported no consistent evidence for benefits, and some evidence for increased disease activity and higher risk of relapse.

Hair, nails, skin
In the United States, biotin is promoted as a dietary supplement for strengthening hair and fingernails, though scientific data supporting these outcomes in humans are very weak.
A review of the fingernails literature reported brittle nail improvement as evidence from two pre-1990 clinical trials that had administered an oral dietary supplement of 2.5 mg/day for several months, without a placebo control comparison group.

There is no more recent clinical trial literature.
A review of biotin as treatment for hair loss identified case studies of infants and young children with genetic defect biotin deficiency having improved hair growth after supplementation, but went on to report that "there have been no randomized, controlled trials to prove efficacy of supplementation with biotin in normal, healthy individuals".
Biotin is also incorporated into topical hair and skin products with similar claims.

The Dietary Supplement Health and Education Act of 1994 states that the US Food and Drug Administration must allow on the product label what are described as "Structure:Function" (S:F) health claims that ingredient(s) are essential for health. For example: Biotin helps maintain healthy skin, hair and nails.
If a S:F claim is made, the label must include the disclaimer "This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease".

Animals
In cattle, biotin is necessary for hoof health.
Lameness due to hoof problems is common, with herd prevalence estimated at 10 to 35%.
Consequences of lameness include less food consumption, lower milk production, and increased veterinary treatment costs.

Results after 4–6 months from supplementing biotin at 20 mg/day into daily diet reduces the risk of lameness.
A review of controlled trials reported that supplementation at 20 mg/day increased milk yield by 4.8%.
The discussion speculated that this could be an indirect consequence of improved hoof health or a direct effect on milk production.

For horses, conditions such as chronic laminitis, cracked hooves, or dry, brittle feet incapable of holding shoes are a common problem. Biotin is a popular nutritional supplement.
There are recommendations that horses need 15 to 25 mg/day.
Studies report biotin improves the growth of new hoof horn rather than improving the status of existing hoof, so months of supplementation are needed for the hoof wall to be completely replaced.

Molar mass: 244.31 g·mol−1
Appearance: White crystalline needles
Melting point: 232 to 233 °C
Solubility in water: 22 mg/100 mL

XLogP3-AA: 0.3
Hydrogen Bond Donor Count: 3
Hydrogen Bond Acceptor Count: 4
Rotatable Bond Count: 5

Exact Mass: 244.08816355 g/mol
Monoisotopic Mass: 244.08816355 g/mol
Topological Polar Surface Area: 104Å²
Heavy Atom Count: 16

Complexity: 298
Isotope Atom Count: 0
Defined Atom Stereocenter Count: 3
Covalently-Bonded Unit Count: 1
Compound Is Canonicalized: Yes

Biotin is an enzyme co-factor present in minute amounts in every living cell.
Biotin is also known as vitamin H or B7 or coenzyme R.
It occurs mainly bound to proteins or polypeptides and is abundant in liver, kidney, pancreas, yeast, and milk.
Biotin has been recognized as an essential nutrient.

Our biotin requirement is fulfilled in part through diet, through endogenous reutilization of biotin and perhaps through capture of biotin generated in the intestinal flora.
The utilization of biotin for covalent attachment to carboxylases and its reutilization through the release of carboxylase biotin after proteolytic degradation constitutes the 'biotin cycle'.

Biotin deficiency is associated with neurological manifestations, skin rash, hair loss and metabolic disturbances that are thought to relate to the various carboxylase deficiencies (metabolic ketoacidosis with lactic acidosis).
It has also been suggested that biotin deficiency is associated with protein malnutrition, and that marginal biotin deficiency in pregnant women may be teratogenic.

Biotin acts as a carboxyl carrier in carboxylation reactions.
There are four biotin-dependent carboxylases in mammals: those of propionyl-CoA (PCC), 3-methylcrotonyl-CoA (MCC), pyruvate (PC) and acetyl-CoA carboxylases (isoforms ACC-1 and ACC-2).
All but ACC-2 are mitochondrial enzymes.

The biotin moiety is covalently bound to the epsilon amino group of a Lysine residue in each of these carboxylases in a domain 60-80 amino acids long.
The domain is structurally similar among carboxylases from bacteria to mammals.
There are four biotin-dependent carboxylases in mammals: those of propionyl-CoA (PCC), 3-methylcrotonyl-CoA (MCC), pyruvate (PC) and acetyl-CoA carboxylases (isoforms ACC-1 and ACC-2). All but ACC-2 are mitochondrial enzymes.

The biotin moiety is covalently bound to the epsilon amino group of a Lys residue in each of these carboxylases in a domain 60-80 amino acids long.
The domain is structurally similar among carboxylases from bacteria to mammals.
Evidence is emerging that biotin participates in processes other than classical carboxylation reactions.

Specifically, novel roles for biotin in cell signaling, gene expression, and chromatin structure have been identified in recent years.
Human cells accumulate biotin by using both the sodium-dependent multivitamin transporter and monocarboxylate transporter 1. These transporters and other biotin-binding proteins partition biotin to compartments involved in biotin signaling: cytoplasm, mitochondria, and nuclei.

The activity of cell signals such as biotinyl-AMP, Sp1 and Sp3, nuclear factor (NF)-kappaB, and receptor tyrosine kinases depends on biotin supply.
Consistent with a role for biotin and its catabolites in modulating these cell signals, greater than 2000 biotin-dependent genes have been identified in various human tissues.
Many biotin-dependent gene products play roles in signal transduction and localize to the cell nucleus, consistent with a role for biotin in cell signaling.

Posttranscriptional events related to ribosomal activity and protein folding may further contribute to effects of biotin on gene expression.
Finally, research has shown that biotinidase and holocarboxylase synthetase mediate covalent binding of biotin to histones (DNA-binding proteins), affecting chromatin structure; at least seven biotinylation sites have been identified in human histones.

Biotinylation of histones appears to play a role in cell proliferation, gene silencing, and the cellular response to DNA repair. Roles for biotin in cell signaling and chromatin structure are consistent with the notion that biotin has a unique significance in cell biology.

Biotin is hexahydro-2-oxo-1H-thieno(3,4-d)imidazole-4-pentanoic acid.
Growth factor present in minute amounts in every living cell.
Biotin occurs mainly bound to proteins or polypeptides and is abundant in liver, kidney, pancreas, yeast, and milk.
The biotin content of cancerous tissue is higher than that of normal tissue.

Biotin is an organic heterobicyclic compound that consists of 2-oxohexahydro-1H-thieno[3,4-d]imidazole having a valeric acid substituent attached to the tetrahydrothiophene ring.
The parent of the class of biotins.
Biotin has a role as a prosthetic group, a coenzyme, a nutraceutical, a human metabolite, a Saccharomyces cerevisiae metabolite, an Escherichia coli metabolite, a mouse metabolite, a cofactor and a fundamental metabolite.
Biotin is a member of biotins and a vitamin B7. It is a conjugate acid of a biotinate.

Biotin is one of eight B vitamins.
Biotin is also known as vitamin B-7 or vitamin H, in which case the H stands for “Haar und Haut,” the German words for “hair and skin.”
Biotin is water-soluble.
The body does not store water-soluble vitamins, so people need to absorb them from their diets.
Biotin is necessary for the function of several enzymes known as carboxylases.

Biotin is a B vitamin that plays a crucial role in the metabolism of carbs, fats, and proteins.
Biotin supports health in many ways.
Biotin deficiencies are relatively rare, but they can cause skin, hair, and nail problems.
Pregnant or breastfeeding women may require more of this vitamin.

Also known as vitamin H, biotin is one of the B complex vitamins that help the body convert food into energy.
The word “biotin” comes from the ancient Greek word “biotos,” which means “life” or “sustenance.”
B vitamins, and specifically biotin, help keep your skin, hair, eyes, liver, and nervous system healthy.
Biotin is also a crucial nutrient during pregnancy, as it’s important for embryonic growth.

Biotin is also known as vitamin B-7. It forms fatty acids and glucose.
Biotin also helps metabolize carbohydrates and amino acids, and it aids in breaking down fat in your body.
These functions make biotin an important part of creating the energy your body needs.
Biotin is found in many foods and beverages, including milk, carrots, salmon, and nuts.
Biotin can also be taken as a supplement if needed.

Biotin (vitamin B7) is a vitamin found in foods like eggs, milk, and bananas.
Biotin deficiency can cause thinning of the hair and a rash on the face.
Biotin is an important part of enzymes in the body that break down substances like fats, carbohydrates, and others.
There isn't a good test for detecting low biotin levels, so it's usually identified by its symptoms, which include thinning hair and red scaly rash around the eyes, nose, and mouth.

Biotin, also called 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 derives from the Greek word “bios” (to live) and the suffix “-in” (a general chemical suffix used in organic chemistry).

Biotin is classified as a heterocyclic compound, with a sulfur-containing ring fused ureido and tetrahydrothiophene group.
A C5-carboxylic acid side chain is appended to one of the rings.
The ureido ring, containing the –N–CO–N– group, serves as the carbon dioxide carrier in carboxylation reactions.
Biotin is a coenzyme for five carboxylase enzymes, which are involved in the digestion of carbohydrates, synthesis of fatty acids, and gluconeogenesis.
Biotinylation of histone proteins in nuclear chromatin plays a role in chromatin stability and gene expression.

Biotin is a coenzyme and a B vitamin.
Biotin is also known as vitamin H.
Because biotin is present in so many different kinds of foods, deficiency is rare.
As a supplement, biotin is sometimes used for hepatitis, brittle nails, neuropathy, and other conditions.

Biotin, a B vitamin, is an essential nutrient that is naturally present in some foods and available as a dietary supplement.
This water-soluble vitamin is a cofactor for five carboxylases (propionyl-CoA carboxylase, pyruvate carboxylase, methylcrotonyl-CoA carboxylase [MCC], acetyl-CoA carboxylase 1, and acetyl-CoA carboxylase 2) that catalyze critical steps in the metabolism of fatty acids, glucose, and amino acids.
Biotin also plays key roles in histone modifications, gene regulation (by modifying the activity of transcription factors), and cell signaling.

Most biotin in foods is bound to protein, although some dietary biotin is in the free form.
Gastrointestinal proteases and peptidases break down the protein-bound forms of ingested biotin into biocytin and biotin-oligopeptides, which undergo further processing by biotinidase, an enzyme, in the intestinal lumen to release free biotin.
The free biotin is then absorbed in the small intestine, and most biotin is stored in the liver.

Biotin is a water-soluble B vitamin found naturally in some foods and also in supplements.
Biotin plays a vital role in assisting enzymes to break down fats, carbohydrates, and proteins in food.
Biotin also helps to regulate signals sent by cells and the activity of genes.

Water-soluble biotin is an essential cofactor to enzymes in intermediary metabolism and a key regulator of gene expression.
Both parenteral nutrition devoid of biotin and prolonged consumption of raw egg white have been associated with symptoms of frank biotin deficiency, including hair loss, dermatitis, and skin rash, ataxia, seizures, and other neurologic dysfunctions.
Biotin is used in the treatment of an inherited disorder of thiamin transport, called biotin-responsive basal ganglia disease, and is currently being tested in trials to limit or reverse functional disabilities in individuals with multiple sclerosis.
Biotin cannot be synthesized by mammalian cells and must be obtained from exogenous sources.
Biotin is widely found in food, and good dietary sources include egg yolk, liver, whole-grain cereal, and some vegetables.

Biotin is a water-soluble vitamin that is generally classified as a B-complex vitamin.
After its initial discovery in 1927, 40 years of additional research was required to unequivocally establish biotin as a vitamin.
Biotin is required by all organisms but can be synthesized by some strains of bacteria, yeast, mold, algae, and some plant species.

Vitamin H, more commonly known as biotin, is part of the B complex group of vitamins.
All B vitamins help the body to convert food (carbohydrates) into fuel (glucose), which is used to produce energy.
These B vitamins often referred to as B complex vitamins, also help the body metabolize fats and protein.
Like all B vitamins, biotin is water-soluble, meaning the body does not store it.
B complex vitamins are needed for healthy skin, hair, eyes, and liver.
They also help the nervous system function properly.

Although rare, biotin deficiency may occur due to:
Taking medications that prevent your body from absorbing the right amount of vitamins.
Intestinal problems that may cause bad nutrient
Dieting as the limited amount of food cannot fulfill the desired amount of vitamins for the body.
Genetic disorders can also be the cause of biotin deficiency.

Biotin is a form of vitamin B that helps your body break down fats, carbohydrates, and proteins.
Small amounts of biotin are found in foods like eggs, milk, and bananas.
Biotin is used as a medical therapy in prescription form to treat a documented biotin deficiency with related symptoms of hair and skin changes.
Biotin’s also sometimes used in children with a specific condition called biotinidase deficiency.

Biotin is a form of vitamin B found in foods.
Biotin helps the body break down fats, carbohydrates, and proteins.
Biotin has been used in alternative medicine as a likely effective aid in treating or preventing biotin deficiency.
Biotin deficiency can be caused by malnutrition, rapid weight loss, long-term tube feeding, and other medical conditions.
Biotin has also been used to treat seborrhea (skin rash) in babies.

Biotin, vitamin B7, is essential for life.
The major biological function of biotin is to act as a covalently bound cofactor for the biological activities of five mammalian biotin-dependent carboxylases.
These biotin-dependent carboxylases have crucial role in essential biological processes including fatty acid synthesis, gluconeogenesis, and amino acid metabolism.
Humans cannot synthesize biotin but the gut bacteria are capable of producing biotin.

The daily biotin requirement (30 μg) is mostly satisfied by diet, so the role of biotin synthesized by gut bacteria in the overall biotin status of humans is not known.
Nutritional biotin deficiency is rare, but consumption of raw eggs on a regular basis may cause biotin deficiency because avidin, a protein present in raw eggs, strongly binds to biotin thus making biotin unavailable for intestinal absorption.
However, cooking eggs denatures avidin and makes biotin available for absorption.

Most biotin in food is protein bound and must be released prior to intestinal absorption.
Biotin is water soluble and as a result free biotin is absorbed almost 100%.
Almost 50% of ingested biotin is excreted unchanged in urine.
Biotin has no known toxicity.

Biotin, a member of the water-soluble B-complex group of vitamins, is synthesized by higher plants and most fungi and bacteria.
Humans, other mammals, and birds cannot synthesize biotin de novo and therefore must obtain this essential micronutrient from material synthesized by intestinal microflora and from dietary sources.
In mammals, absorption of biotin occurs in the small intestine.
Other important sites that play a role in normal biotin physiology include the liver (the principal site of biotin utilization), kidney (the site of reabsorption of filtered biotin), and placenta (the site of transport of biotin from the maternal circulation to the developing embryo).

Biotin obtained from dietary sources exists in both free and protein-bound forms.
Protein-bound biotin is digested by gastrointestinal proteases and peptidases to biocytin and biotin-containing short peptides.
Biotin present in these compounds is recycled through the action of biotinidase to release free biotin.

Biotin is a water-soluble vitamin of the B complex (vitamin B7, also called vitamin H), and is found in many foods, especially eggs and liver.
Biotin is involved in the action of four carboxylases:

acetyl-CoA carboxylase, which catalyses the binding of bicarbonate to acetyl-CoA to form malonyl-CoA in the synthesis of fatty acids;
pyruvate carboxylase, which is involved in gluconeogenesis;
methylcrotonyl-CoA carboxylase, which catalyses an essential step in the metabolism of leucine;
propionyl-CoA carboxylase, which catalyses essential steps in the metabolism of amino acids, cholesterol, and fatty acids.

Biotin, also known as vitamin B7 or vitamin H, is an essential vitamin because it acts as a cofactor for five biotin-dependent carboxylases that play critical roles in the intermediate metabolism of gluconeogenesis, fatty acid synthesis, and amino acid catabolism.

Biotin is covalently attached to the enzyme through an amide bond that links the carboxyl group of the valeric acid side chain of biotin to the ɛ-amino group of a lysine residue in apoenzyme.
This reaction is catalyzed in a two-step reaction by biotin protein ligase, a protein called BirA, which is also the repressor protein that regulates transcription of the bio operon in E. coli

Biotin is a water-soluble, enzyme co-factor present in minute amounts in every living cell.
Biotin occurs mainly bound to proteins or polypeptides and is abundant in liver, kidney, pancreas, yeast, and milk.

Biotin is a water-soluble B-complex vitamin which is composed of an ureido ring fused with a tetrahydrothiophene ring, which attaches a valeric acid substituent at one of its carbon atoms. Biotin is used in cell growth, the production of fatty acids, metabolism of fats, and amino acids.
Biotin plays a role in the Kreb cycle, which is the process in which energy is released from food.
Biotin not only assists in various metabolic chemical conversions, but also helps with the transfer of carbon dioxide.
Biotin is also helpful in maintaining a steady blood sugar level.

Biotin is often recommended for strengthening hair and nails.
Consequently, it is found in many cosmetic and health products for the hair and skin.
Biotin deficiency is a rare nutritional disorder caused by a deficiency of biotin.
Initial symptoms of biotin deficiency include: Dry skin, Seborrheic dermatitis, Fungal infections, rashes including erythematous periorofacial macular rash, fine and brittle hair, and hair loss or total alopecia.

If left untreated, neurological symptoms can develop, including mild depression, which may progress to profound lassitude and, eventually, to somnolence; changes in mental status, generalized muscular pains (myalgias), hyperesthesias and paresthesias.
The treatment for biotin deficiency is to simply start taking some biotin supplements.
A lack of biotin in infants will lead to a condition called seborrheic dermatitis or "cradle cap".
Biotin deficiencies are extremely rare in adults but if it does occur, it will lead to anemia, depression, hair loss, high blood sugar levels, muscle pain, nausea, loss of appetite and inflamed mucous membranes.

Biotin is necessary for the proper functioning of enzymes that transport carboxyl units and fix carbon dioxide, and is required for various metabolic functions, including gluconeogenesis, lipogenesis, fatty acid biosynthesis, propionate metabolism, and catabolism of branched-chain amino acids.

Biotin is a water-soluble B-vitamin, also called vitamin B7 and formerly known as vitamin H or coenzyme R.
Biotin is composed of a ureido ring fused with a tetrahydrothiophene ring.
A valeric acid substituent is attached to one of the carbon atoms of the tetrahydrothiophene ring.
Biotin is a coenzyme for carboxylase enzymes, involved in the synthesis of fatty acids, isoleucine, and valine, and in gluconeogenesis.

Biotin is a vitamin that is found in small amounts in numerous foods.
Biotin is used for preventing and treating biotin deficiency associated with pregnancy, long-term tube feeding, malnutrition, and rapid weight loss.
Biotin is also used orally for hair loss, brittle nails, skin rash in infants (seborrheic dermatitis), diabetes, and mild depression.

Vitamin H, more commonly known as biotin, is part of the B complex group of vitamins.
All B vitamins help the body to convert food (carbohydrates) into fuel (glucose), which is used to produce energy.
These B vitamins, often referred to as B complex vitamins, also help the body metabolize fats and protein.
B complex vitamins are needed for healthy skin, hair, eyes, and liver. They also help the nervous system function properly.

Your body needs biotin to metabolize carbohydrates, fats, and amino acids, the building blocks of protein.
Biotin is often recommended for strengthening hair and nails, and it's found in many cosmetic products for hair and skin.

Like all B vitamins, Biotin is a water soluble, meaning the body does not store it.
However, bacteria in the intestine can make biotin. It is also available in small amounts a number of foods.
Biotin is also important for normal embryonic growth, making it a critical nutrient during pregnancy.
It’s rare to be deficient in biotin.
Symptoms include hair loss, dry scaly skin, cracking in the corners of the mouth (called cheilitis), swollen and painful tongue that is magenta in color (glossitis), dry eyes, loss of appetite, fatigue, insomnia, and depression.

Biotin is a type of vitamin B, specifically B7.
Unlike vitamin C or vitamin D, there are many types of B vitamins that each play their own important role in maintaining how your body functions.
In particular, biotin stands apart from the rest with its role in keeping skin, hair, and nails healthy and looking vibrant.

B vitamins fuel many delicate, intricate pathways in the body, like methylation—your body's biochemical superhighway, a process that happens more than 1 billion times every single second. This pathway is responsible for decreasing the body's inflammatory response; it also helps your body in breaking down food for energy production.
Biotin's role in energy production is perhaps its most important: Biotin is considered a coenzyme for carboxylases, which are the enzymes that assist in metabolizing fats, carbohydrates, and proteins, turning these macronutrients into your body's fuel.
The enzymes also aid in processes such as gluconeogenesis, insulin release, fatty acid synthesis, and the use of branched-chain amino acids to produce neurotransmitters.

Biotin, water-soluble, nitrogen-containing acid essential for growth and well-being in animals and some microorganisms.
Biotin is a member of the B complex of vitamins.
Biotin functions in the formation and metabolism of fats and carbohydrates.
A relatively stable substance, Biotin is widely distributed in nature and is especially abundant in egg yolk, beef liver, and yeast.

Biotin is a B vitamin.
Biotin’s water-soluble.
Biotin’s easily absorbed when you take it by mouth.
Biotin’s found in a variety of foods.

Biotin’s also made by bacteria inside the large intestine.
Biotin deficiency is rare.
Like the other B vitamins, biotin helps your body make energy.

Biotin works with carboxylase enzymes, ATP, and magnesium to use carbon dioxide to help make fatty acids.
Biotin also helps make proteins and purines.
Biotin helps your body break down carbohydrates and the amino acid tryptophan.

Although Biotin is one of the lesser-known B vitamins, it plays a significant role in several metabolic processes.
Biotin is vital in the metabolism of proteins, fats, and carbohydrates from food.
Biotin is involved in fatty acid biosynthesis, energy production, and synthesis of some amino acids such as BCAA.
Recent research suggests that Biotin could be significant in gene expression as well as in DNA replication.

Biotin, also known as vitamin H or vitamin B7, is an essential nutrient with many health benefits including converting food to fuel and maintaining healthy skin, hair, and nails.
Biotin is a small molecule and its presence with biologically active macromolecules does not affect the biological function of the macromolecule.
The biotin-(strept)avidin system are required for various applications.
Biotin also works as a cofactor of carboxylating enzymes, such as pyruvate carboxylase.

Biotin catalyzes the formation of oxaloacetate from pyruvate and CO2.
Biotin conjugation with avidin or streptavidin helps in linking the target molecule (antibody, nucleotide, protein A etc.) with the labeling system (enzyme, fluorescent, chemiluminescent probes).
This complex is used for many detection systems, such as immunoassays, DNA hybridization assays, immunohistochemistry and flow-cytometry.
This approach is also applied for the purification and characterization of various molecules of interest.

Biotin may be used to elute proteins from avidin/streptavidin resins.
Biotin has been used for culturing of oligodendrocytes.
Biotin has been used as a vitamin supplement for the growth of Bacillus species.
Biotin has been used for blocking endogenous biotin during immunohistology procedures.

Biotin is a water-soluble vitamin that belongs to the vitamin B family.
Biotin’s necessary for the production of keratin, a protein that is a structural component of hair, nails and skin.

In mammals, biotin serves as a covalently bound coenzyme for 5 carboxylases: acetyl-CoA carboxylases 1 and 2, propionyl-CoA carboxylase (PCC), 3-methylcrotonyl-CoA carboxylase (MCC), and pyruvate carboxylase.
Acetyl-CoA carboxylase 1 localizes in the cytoplasm, where it catalyzes the binding of bicarbonate to acetyl-CoA in a key step in fatty acid synthesis.
All other carboxylases localize in mitochondria.
PCC catalyzes an essential step in the metabolism of propionyl-CoA, which originates in the catabolism of odd-chain fatty acids and some other nutrients.
MCC catalyzes a key step in the metabolism of the amino acid leucine.
Pyruvate carboxylase catalyzes the conversion of pyruvate to oxaloacetate, which is a key step in gluconeogenesis.

Holocarboxylase synthetase (HLCS) catalyzes the binding of biotin to all 5 carboxylases and, therefore, plays a pivotal role in biotin-dependent metabolic pathways.
In addition, HLCS participates in gene regulation at the chromatin level.
Consistent with the important roles of HLCS in biotin metabolism, no living HLCS null individual has ever been reported, suggesting embryonic lethality.
Mutations have been identified and characterized in the human HLCS gene; these mutations cause a substantial decrease in HLCS activity and metabolic abnormalities.
Some mutations respond well to pharmacological doses of biotin if diagnosed early.

Biotinidase catalyzes the release of biotin from breakdown products of carboxylases and, therefore, plays a crucial role in biotin recycling.
Mutations in the biotinidase gene impair the recycling of biotin and lead to a substantial urinary loss of biotin in form of biotinylated peptides.
Afflicted patients are treated with pharmacological doses of biotin to compensate for the urinary loss of biotin.
Biotin affects gene regulation by “classic” signaling pathways such as cyclic guanosine monophosphate, nuclear factor-κB, Sp1 and Sp3, nitric oxide, and receptor tyrosine kinases, by the intermediate biotinyl-5′-adenosyl monophosphate, and at the posttranscriptional level.

Biotin, or vitamin H is part of the complex B vitamins.
Along with helping the body metabolize fats and carbohydrates, biotin has been linked to improved hair health and maintaining proper function of the nervous system.
Though it’s uncommon to have a deficiency in biotin, chronic smokers, alcoholics, pregnant women, those with Crohn’s and/or liver disease and anyone eating a diet loaded with processed foods are most likely to have a deficiency.
Symptoms often reveal themselves through dry eyes, cracking on the sides of the mouth, scaly skin, depression and hair loss.

Biotin crystallizes from water as long, white needles. Its melting point is 232° to 233°C.
Free biotin is soluble in dilute alkaline solutions and hot water and practically insoluble in fats and organic solvents.
Biotin is quite stable under ordinary conditions.
Biotin is destroyed by nitric acid, other strong acids, strong bases and formaldehyde, and also is inactivated by oxidative rancidity reactions.

Biotin is gradually destroyed by ultraviolet (UV) radiation.
Structurally related analogs of biotin can vary from no activity, to partial replacement of biotin activity, to anti-biotin activity.
Mild oxidation converts biotin to the sulfoxide, and strong oxidation converts it to sulfone.
Strong agents result in sulfur replacement by oxygen, resulting in oxybiotin and desthiobiotin.

Biotin is a member of the family of B vitamins (specifically, B7) that can be found naturally in a variety of foods including whole grains, egg yolks, walnuts and avocados.
The components making up Biotin offer a number of benefits.
Biotin supports cellular energy metabolism.
And Biotin may also help support healthy hair, skin and nails for anyone who may have a biotin deficiency

Vitamin B7, also called biotin, is a vital part of a healthy metabolism and creating important enzymes.
Biotin is often used to strengthen hair and nails, and is also called Vitamin H (for hair).
Biotin is found in small amounts in food.
Foods that contain biotin are liver, cauliflower, salmon, carrots, bananas, soy flour, yeast, wheat germ, whole-grain cereals, whole wheat bread, eggs, dairy products, nuts, Swiss chard and chicken.

Biotin, also known as vitamin B7 or vitamin H, is a water-soluble vitamin.
Biotin is essential for a group of enzymes called carboxylases, which are essential for the metabolism of carbohydrates, proteins, and fatty acids into energy.
Biotin also helps in the regulation of signals sent by cells, and in gene activity.
Some amount of biotin can be found in many foods.

Good sources of biotin include beef, organ meats, poultry, cooked eggs, fish (e.g., salmon), seeds, nuts, and some vegetables like sweet potatoes.
Biotin can also be synthesized by intestinal bacteria.
An organic heterobicyclic compound that consists of 2-oxohexahydro-1H-thieno[3,4-d]imidazole having a valeric acid substituent attached to the tetrahydrothiophene ring.

Vitamin B7, more commonly known as biotin, is a water-soluble vitamin that is vital for the body’s metabolism and functioning.
Biotin is an essential component of a number of enzymes responsible for several crucial metabolic pathways in the human body, including the metabolism of fats and carbohydrates, as well as amino acids involved in protein synthesis.
Biotin is known to promote cell growth and is often a component of dietary supplements used for strengthening hair and nails, as well as those marketed for skin care.

Biotin is a vitamin involved in the metabolism of carbohydrates, fats, and amino acids, the building blocks of protein.
Like all B vitamins, it helps the body convert the carbohydrates from food into glucose (blood sugar), which is used to produce energy to fuel the body.
In addition, biotin helps regulate DNA and the production of cellular structures inside the human body.
Many people also consider biotin the “beauty” vitamin, because it helps promote healthy-looking hair, nails, and skin.
Because it is water-soluble, excess amounts of biotin are excreted in urine.

The vitamin B-complex includes essential water-soluble vitamins such as thiamine (vitamin B1), riboflavin (vitamin B2), niacin (vitamin B3), pantothenic acid (vitamin B5), pyridoxine (vitamin B6), biotin (vitamin B7), folic acid, and the cobalamins (vitamin B12). Biotin and vitamins B1, B2, and B3 are involved in different aspects of energy production and other bodily functions.
Vitamin B6 assists with amino acid metabolism, and vitamin B12 and folic acid support cell division.
Research suggests that vitamin B-complex multi vitamins may support wound healing, a healthy mood, athletic performance, digestion, bone health, and healthy-looking hair, skin, and nails.

Biotin is an essential coenzyme for carboxylases, which are enzymes that play an important role in metabolic pathways, including in the production of glucose and fatty acids, as well as other cellular processes.
A proper amount of biotin in the human diet helps maintain normal body functions, especially in the heart muscle and brain.
Biotin is also linked to histones (DNA-binding proteins).
When biotin is molecularly bound to protein, such as histone H4, this “biotinylation” process supports DNA repair and genome stability, minimizing cellular risk for oxidation.

Biotin, also known as vitamin B7, is a water-soluble vitamin that plays a vital role in metabolism, gene regulation, and cell signaling.
Biotin’s a type of vitamin called a co-factor, meaning it helps enzymes break down fatty acids, glucose and amino acids so your body can function properly.
While biotin gained fame as a beauty booster, it does more than keep your hair, nails and skin healthy.

Vitamin B7, also known as Biotin is one of the water-soluble and highly essential B-complex vitamins.
Termed as Vitamin H where the letter ‘H’ represents’ Haar und Haut’, which are German words for "hair and skin", it is pivotal for a wide range of metabolic processes in the body including enzyme synthesis for several crucial metabolic pathways’ metabolism of fats and carbohydrates, as well as synthesis of amino acids which are necessary for protein synthesis.
Primarily, Biotin is a type of co-enzyme that is required for the synthesis of fatty acids which are molecules found in fats and oils; glucogenesis, i.e. synthesis of glucose from amino acids and fatty acids; and synthesis of leucine, a quintessential amino acid that the human body cannot generate on its own.

Biotin is synthesized by only bacteria, molds, yeasts, algae, and certain plants.
The human body cannot synthesise biotin on its own and has to depend on outer dietary sources to replenish the required amount.
Biotin is extremely essential in maintaining good hair, skin, and nails.
Biotin improves neural functioning and helps in the metabolism of nutrients.

Biotin was discovered in the year 1931 by German scientist Paul Gyorgy when he extracted the compound from the liver and named in Vitamin H.
Biotin is also listed as one of the safest and effective medicines in the World Health Organization's List of Essential Medicines.

Biotin is a water-soluble vitamin that is part of the B vitamin family.
Biotin’s also known as vitamin H, vitamin B7 or vitamin B8 and is one of the vitamins that helps your body convert food into energy.

Benefits and function:
Biotin plays a number of important roles in the body, including:
Breaking down macronutrients:

Biotin helps the body convert food into energy — it supports a number of enzymes involved in the breakdown of carbs, fats, and proteins.
Specifically, biotin is involved in:

Gluconeogenesis: This is the synthesis of glucose from sources other than carbs, such as amino acids, and biotin-containing enzymes help initiate this process.
Fatty acid synthesis: Biotin assists enzymes that activate reactions that are important for the production of fatty acids.
Amino acid breakdown: Biotin-containing enzymes are involved in the metabolism of several important amino acids, including leucine.

Supporting nail health
Brittle nails are fragile and easily become split or cracked.
A biotin deficiency can lead to brittle nails.
For people with this deficiency, taking supplements that contain biotin could improve the strength of their nails.
Changing the diet and other lifestyle factors can help improve nail health, as can some commercial products.

Boosting hair health:
The diet can play an important role in the health of the skin and hair.
For instance, some foods for healthy hair include eggs, Brazil nuts, and fatty fish.
Many hair products that claim to encourage healthier, stronger hair contain biotin.
Biotin deficiency can lead to hair loss, which indicates that the vitamin is involved in keeping the hair healthy.

Boosting skin health:
People with biotin deficiencies may experience skin problems, including red, scaly rashes.
Some people also believe that biotin may help improve psoriasis.
The vitamin’s influence on the skin may stem from its effect on fat metabolism.
This process is important for maintaining healthy skin, and it may be impaired in people with low levels of biotin.

In addition, gut bacteria produce some biotin.
Some people take supplements that either contain biotin on its own or in a combination of vitamins.

Biotin provides an important source for creating energy as well as maintaining the function of your body as a whole.
Like all vitamins, your body needs biotin to stay healthy. There are several systems that biotin helps keep healthy.
Some of these include your liver, nervous system, hair, eyes, and more.
Biotin may be effective in treating certain medical conditions.

Biotin is one of several B vitamins that support a healthy metabolism.
Biotin converts glucose from carbohydrates into energy for the body and aids amino acids in carrying out normal bodily functions.
Biotin is an essential vitamin—meaning that your body needs this micronutrient to function properly.
The biotin you consume in foods helps your body turn the food you eat (protein, carbohydrates, and fat) into energy.
Manufacturers claim that shampoo, conditioner, hair oils, masks, and creams containing biotin can thicken hair, increase fullness, and add shine.
A handful of research studies have shown that biotin supplementation may help stimulate hair regrowth in people who have a clinical biotin deficiency or alopecia

Biotin functions as a covalently bound cofactor required for the biological activity of the five known mammalian biotin-dependent carboxylases.
Such a non-protein cofactor is known as a "prosthetic group."
The covalent attachment of biotin to the apocarboxylase (i.e., catalytically inactive carboxylase) is catalyzed by the enzyme, holocarboxylase synthetase (HCS).
The term "biotinylation" refers to the covalent addition of biotin to any molecules, including apocarboxylases and histones.

HCS catalyzes the post-translational biotinylation of the epsilon amino group of a lysine residue at the active site of each apocarboxylase, converting the inactive apocarboxylase into a fully active holocarboxylase.
Particular lysine residues within the N-terminal tail of specific histones, which help package DNA in eukaryotic nuclei, can also be biotinylated.
Biotinidase is the enzyme that catalyzes the release of biotin from biotinylated histones and from the peptide products of holocarboxylase breakdown.

Biotin treat arteriosclerosis, stroke, lipid metabolism disorders, hypertension, coronary heart disease and blood circulation obstacle disease.
Used in cosmetics, can improve blood circulation in the skin blood vessels in the rate of 0.1% ~ 1.0% of the concentration range,easy-to-formula mixed in the oil phase.
In the skin care cream, sports liquid legs with analgesic cream, shaving liquid, shampoo can be used in.
Preliminary research suggests that supplemental biotin might help reduce blood sugar levels in people.
Biotin possibly reduce the symptoms of diabetic neuropathy.

Supports hair health.
Thinning hair and hair loss are very common symptoms of biotin deficiency and can be supported with a supplement.
Additionally, biotin is believed to naturally promote healthy hair growth because it is involved in the production of keratin, the main component of hair.

Supports skin health.
Biotin is right there at the front line to fight the effects of aging with its role in fatty acid synthesis, which is crucial for healthy skin.
The cells in your skin depend heavily on fat production for added protection against damage from pollution, sun, and other harsh everyday environmental concerns.

Promotes nail strength.
Brittle, rigid nails are another common complaint for those with vitamin deficiencies, especially vitamin B deficiencies.
Biotin has been shown to support thickness and firmness of nails in several human studies.

Supports immune health.
Biotin is essential for maintaining the development of white blood cells.
These are the defense mechanisms of your immune system and work to protect your body against viruses and bacteria that make you sick.
Your body actually contains two different types of white blood cells, called TH1 and TH2.

Almost like a seesaw, TH1 and TH2 need to balance each other.
When one becomes dominant, it can trigger an inflammatory response in your body.
One reason this can happen is a lack of T-regulatory cells, which work to maintain balance.
Biotin deficiency is associated with T-cell decay.

Supports brain function.
Biotin, along with other B vitamins, plays a role in neurotransmitter activity and protects against neurodegenerative disorders like age-related cognitive decline and overall aids in supporting cognitive function.
Biotin also helps to maintain mood due to their role in synthesizing hormones responsible for a positive mood.
Deficiency in biotin can lead to neurological problems, which has biotin supplementation has been shown to support.

Biotin can act as an anti-inflammatory.
Studies have shown that biotin deficiency can increase pro-inflammatory cytokines and contribute to inflammation.
Biotin works by activating the inflammatory nuclear factor kappa B (NF-kB for short), which binds to your DNA and triggers a number of inflammatory cascades throughout the body.
Research has shown that supplementing with biotin can maintain healthy levels of these pro-inflammatory cytokines.

Supports heart health.
Biotin is needed for fat metabolism, which is important for thriving heart health.
Biotin can also work in conjunction with chromium to reduce LDL levels and increase HDL since inverse levels of each are markers for increased risk of heart disease.
Research has shown that a dose of 15,000 mcg a day of biotin can also maintain healthy blood triglyceride levels.

Supports nutrient breakdown in the body.
In every cell of your body, biotin helps break down the nutrients (protein amino acids, carbohydrates, and fatty acids) from your food for fuel.
B7 is also über-important whenever we are doing different forms of fasting (such as intermittent fasting) or if you are in a ketogenic state (nutritional ketosis or fat burning).
During these metabolic states, biotin is needed to support new glucose for fuel through gluconeogenesis.

The main benefit of biotin is that it supports a healthy metabolism by converting food into fuel.
Specifically, Biotin metabolizes fats and breaks protein down into amino acids, which we then use to build muscle and repair tissues.

Consuming adequate amounts of biotin is crucial for hair and nail health.
That's because biotin helps produce natural oils in the scalp that help your hair stay healthy.
In fact, a 2017 scientific review found that biotin supplementation improved hair and nail growth, in people who had underlying conditions that cause weak nails or hair loss, like brittle nail syndrome or uncombable hair syndrome.

Biotin is essential for the body’s metabolism.
Biotin acts as a coenzyme in a number of metabolic pathways involving fatty acids and essential amino acids, as well as in gluconeogenesis – the synthesis of glucose from non-carbohydrates. Although biotin deficiency is rare, some groups of people may be more susceptible to it, such as patients suffering from Crohn’s disease.
Biotin deficiency symptoms include hair loss, skin issues including rash, an appearance of cracking in the corners of the mouth, dryness of the eyes and appetite loss.
Vitamin B7 promotes appropriate function of the nervous system and is essential for liver metabolism as well.

Biotin is commonly advised as a dietary supplement for strengthening hair and nails, as well as in skin care.
Biotin is suggested that biotin aids cell growth and the maintenance of mucous membranes.
Although biotin may be present in certain cosmetics, it is important to remember that it cannot actually be absorbed through skin, hair or nails.

Vitamin B7 can aid in caring for thinning hair and brittle nails, especially in those suffering from biotin deficiency.
Some evidence has shown that those suffering from diabetes may be susceptible to biotin deficiency.
Since biotin is an important factor in the synthesis of glucose, it may help maintain an appropriate blood sugar level in patients suffering from type 2 diabetes.

Biotin is an essential vitamin that has many benefits, such as:
Being an energy source for cells, since it's essential for the production of glycogen, which also helps regulate glucose levels.
Stimulating the production of proteins, as it aids in the formation of amino acids, which are the building blocks of proteins.
Strengthening hair and nails, since it guarantees the production of proteins that are essential for healthy nails and hair.

Promoting skin health, because it ensures the body produces collagen and keratin, which are essential proteins to guarantee skin elasticity and resistance.
Increasing the reabsorption of vitamins B12, B5 and folic acid, which help to maintain optimal body functions.
Helping form blood cells, especially lymphocytes and antibodies.
In addition, biotin can also help keep the nervous system healthy, help in the treatment of acne and hair loss and control cholesterol levels.
Although Biotin cannot be absorbed by hair or skin, it contributes towards healthy nails, skin and hair, and hence plays a key role and feature in many cosmetic and health products used for enhancing the skin and hair quality.

Biotin is extremely essential for hair, skin and nails.
Biotin improves the texture of the skin by preventing oxidative damage.
Biotin also rejuvenates and moisturises the skin, reduces various signs of ageing like wrinkles, fine lines, spots, dark circles etc, making it crystal clear.
In case of the hair, biotin is pivotal for strengthening the hair from the root to the tips.
Biotin retains the natural colour of the hair and prevents breakage and hair fall.

Biotin locks the moisture in the hair strands and prevents the hair from turning brittle.
Daily intake of food and supplements containing biotin is also beneficial for nails.
Biotin is also extremely beneficial in improving nail quality and preventing brittle nails.

Vitamin B7 is also essential in improving the cognitive functioning of the brain.
Biotin helps in repairing the brain cells and in turn, is used for treating symptoms associated with psychotic conditions like brain fog, depression, schizophrenia, hallucinations, etc.
it also treats biotin responsive basal ganglia disease and hence promotes healthy functioning of the nervous system.

Biotin is helpful in the case of people suffering from kidney problems.
Biotin also effectively reduces muscle cramps and pain during dialysis.
Biotin is also beneficial for improving vision and treating conditions like seborrheic dermatitis, cradle cap in children and auto-immune diseases like multiple sclerosis in adults.
Biotin is also extremely crucial in promoting the health of the baby in pregnant women and even after birth.