Biotin – Consumer

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What is biotin and what does it do?

Biotin is a B-vitamin found in many foods. Biotin helps turn the carbohydrates, fats, and proteins in the food you eat into the energy you need.

How much biotin do I need?

The amount of biotin you need each day depends on your age. Average daily recommended amounts are listed below in micrograms (mcg).

What foods provide biotin?

Many foods contain some biotin. You can get recommended amounts of biotin by eating a variety of foods, including the following:

• Meat, fish, eggs, and organ meats (such as liver)
• Seeds and nuts
• Certain vegetables (such as sweet potatoes, spinach, and broccoli)

What kinds of biotin dietary supplements are available?

Biotin is found in some multivitamin/multimineral supplements, in B-complex supplements, and in supplements containing only biotin.

Am I getting enough biotin?

Most people get enough biotin from the foods they eat. However, certain groups of people are more likely than others to have trouble getting enough biotin:

• People with a rare genetic disorder called “biotinidase deficiency”
• People with alcohol dependence
• Pregnant and breastfeeding women

What happens if I don’t get enough biotin?

Biotin deficiency is very rare in the United States. Biotin deficiency can cause thinning hair and loss of body hair; a rash around the eyes, nose, mouth, and anal area; pinkeye; high levels of acid in the blood and urine; seizures; skin infection; brittle nails; and nervous system disorders. Symptoms of biotin deficiency in infants include weak muscle tone, sluggishness, and delayed development.

What are some effects of biotin on health?

Scientists are studying biotin to understand how it affects health. Here is an example of what this research has shown.

Hair, nail, and skin health
Dietary supplements that contain biotin are often promoted to improve the health of your hair, skin, and nails, but there is little scientific evidence to support these claims. In a few small studies, some people with thin and brittle nails who took high doses of biotin had harder nails. Doctors have also reported that in a few cases, high doses of biotin have improved a rare hair disorder in children and skin rash in infants. More research is needed before biotin supplements can be recommended for any of these conditions.

Can biotin be harmful?

Biotin has not been shown to cause any harm. However, supplements that contain biotin above recommended amounts may cause false results in some lab tests, including those that measure levels of certain hormones, like thyroid hormone.

Does biotin interact with medications or other dietary supplements?

Yes, some medications you take may affect your biotin levels, and biotin may interact with certain medications. For example, treatment for at least 1 year with antiseizure medications (used to treat epilepsy) can significantly lower biotin levels.

Tell your doctor, pharmacist, and other health care providers about any dietary supplements and prescription or over-the-counter medicines you take. They can tell you if the dietary supplements might interact with your medicines or laboratory tests, or if the medicines might interfere with how your body absorbs, uses, or breaks down nutrients such as biotin.

Biotin and healthful eating

People should get most of their nutrients from food and beverages, according to the federal government’s Dietary Guidelines for Americans. Foods contain vitamins, minerals, dietary fiber and other components that benefit health. In some cases, fortified foods and dietary supplements are useful when it is not possible to meet needs for one or more nutrients (for example, during specific life stages such as pregnancy). For more information about building a healthy dietary pattern, see the Dietary Guidelines for Americans and the U.S. Department of Agriculture’s MyPlate.

Where can I find out more about biotin?

• For general information about biotin:
  • Office of Dietary Supplements Health Professional Fact Sheet on Biotin

• For more information on food sources of biotin:
  • Office of Dietary Supplements Health Professional Fact Sheet on Biotin

• For more advice on choosing dietary supplements:
  • Office of Dietary Supplements Frequently Asked Questions: Which brand(s) of dietary supplements should I purchase?

• For information about building a healthy dietary pattern:
  • MyPlate
  • Dietary Guidelines for Americans

Disclaimer

This fact sheet by the National Institutes of Health (NIH) Office of Dietary Supplements (ODS) provides information that should not take the place of medical advice. We encourage you to talk to your health care providers (doctor, registered dietitian, pharmacist, etc.) about your interest in, questions about, or use of dietary supplements and what may be best for your overall health. Any mention in this publication of a specific product or service, or recommendation from an organization or professional society, does not represent an endorsement by ODS of that product, service, or expert advice.

Updated:
January 15, 2021
History of changes to this fact sheet

Biotin | Dietary Reference Intakes: The Essential Guide to Nutrient Requirements

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

TABLE 1 Dietary Reference Intakes for Biotin by
Life Stage Group
DRI values (mg/day)
AIa ULb
Life stage groupc
0 through 6 mo 5
7 through 12 mo 6
1 through 3 y 8
4 through 8 y 12
9 through 13 y 20
14 through 18 y 25
19 through 30 y 30
31 through 50 y 30
51 through 70 y 30
> 70 y 30
Pregnancy
£ 18 y 30
19 through 50 y 30
Lactation
£ 18 y 35
19 through 50 y 35
a AI = Adequate Intake.
b UL = Tolerable Upper Intake Level. Data were insufficent to set a UL. In the
absence of a UL, extra caution may be warranted in consuming levels above the
recommended intake.
c All groups except Pregnancy and Lactation represent males and females.

PART III: BIOTIN 197
BIOTIN
B
iotin functions as a coenzyme in bicarbonate-dependent carboxylation
reactions. It exists both as free biotin and in protein-bound forms in
foods. Little is known about how protein-bound biotin is digested.
Since data were insufficient to set an Estimated Average Requirement (EAR)
and thus calculate a Recommended Dietary Allowance (RDA) for biotin, an
Adequate Intake (AI) was instead developed. The AIs for biotin are based on
data extrapolation from the amount of biotin in human milk. Data were insuf-
ficient to set a Tolerable Upper Intake Level (UL). DRI values are listed by life
stage group in Table 1.
The biotin content of foods is generally not documented. It is widely dis-
tributed in natural foods, but its concentration varies. Signs of biotin deficiency
have been conclusively demonstrated in individuals consuming raw egg whites
over long periods and in patients receiving total parenteral nutrition (TPN)
solutions that do not contain biotin. No adverse effects have been documented
for biotin at any intake tested.
BIOTIN AND THE BODY
Function
Biotin functions as a coenzyme in bicarbonate-dependent carboxylation
reactions.
Absorption, Metabolism, Storage, and Excretion
Biotin exists both as free biotin and in protein-bound forms in foods. Little is
known about how protein-bound biotin is digested. It appears to be absorbed
in both the small intestine and the colon. The mechanism of biotin transport to
the liver and other tissues after absorption has not been well established. Avi-
din, a protein found in raw egg white, has been shown to bind to biotin in the
small intestine and prevent its absorption. The mechanism of biotin transport
to the liver and other tissues after absorption has not been well established.
Biotin is excreted in the urine.

DRIs: THE ESSENTIAL GUIDE TO NUTRIENT REQUIREMENTS
198
DETERMINING DRIS
Determining Requirements
Since data were insufficient to establish an EAR and thus calculate an RDA, an
AI was instead developed. The AIs for biotin are based on extrapolation from
the amount of biotin in human milk. Most major nutrition surveys do not re-
port biotin intake.
Special Considerations
Individuals with increased needs: People who receive hemodialysis or perito-
neal dialysis may have an increased requirement for biotin, as do those with
genetic biotinidase deficiency.
Criteria for Determining Biotin Requirements,
by Life Stage Group
Life stage group Criterion
0 through 6 mo Human milk content
7 through 12 mo Extrapolation from infants
1 through > 70 y Extrapolation from infants
Pregnancy
£ 18 through 50 y Extrapolation from infants
Lactation
£ 18 through 50 y To cover the amount of biotin secreted in milk, the AI is
increased by 5 mg/day
The UL
The Tolerable Upper Intake Level (UL) is the highest level of daily nutrient
intake that is likely to pose no risk of adverse effects for almost all people. Due
to insufficient data on the adverse effects of excess biotin consumption, a UL for
biotin could not be determined.
DIETARY SOURCES
Foods
Biotin content has been documented for relatively few foods, and so it is gener-
ally not included in food composition tables. Thus, intake tends to be underes-

PART III: BIOTIN 199
timated in diets. Although biotin is widely distributed in natural foods, its con-
centration significantly varies. For example, liver contains biotin at about 100
mg/100 g, whereas fruits and most meats contain only about 1 mg/100 g.
Dietary Supplements
According to the 1986 National Health Interview Survey (NHIS), approximately
17 percent of U.S. adults reported taking a supplement that contained biotin.
Specific data on intake from supplements were not available.
Bioavailability
This information was not provided at the time the DRI values for this nutrient
were set.
Dietary Interactions
This information was not provided at the time the DRI values for this nutrient
were set.
INADEQUATE INTAKE AND DEFICIENCY
Signs of biotin deficiency have been conclusively demonstrated in individuals
consuming raw egg whites over long periods and in patients receiving total
parenteral nutrition (TPN) solutions that do not contain biotin. The effects of
biotin deficiency include the following:
• Dermatitis (often appearing as a red scaly rash around the eyes, nose,
and mouth)
• Conjunctivitis
• Alopecia
• Central nervous system abnormalities, such as depression, lethargy, hal-
lucinations, and paresthesia of the extremities
Symptoms of deficiency in infants on biotin-free TPN appear much earlier after
the initiation of the TPN regimen than in adults. In biotin-deficient infants,
hypotonia, lethargy, and developmental delays, along with a peculiar withdrawn
behavior, are all characteristic of a neurological disorder resulting from a lack of
biotin.

DRIs: THE ESSENTIAL GUIDE TO NUTRIENT REQUIREMENTS
200
EXCESS INTAKE
There have been no reported adverse effects of biotin in humans or animals.
Toxicity has not been reported in patients given daily doses of biotin up to 200
mg orally and up to 20 mg intravenously to treat biotin-responsive inborn er-
rors of metabolism and acquired biotin deficiency.

KEY POINTS FOR BIOTIN
Biotin functions as a coenzyme in bicarbonate-dependent
3
carboxylation reactions.
Since data were insufficient to establish an EAR and thus
3
calculate an RDA, an AI was instead developed.
The AIs for biotin are based on extrapolation from the amount
3
of biotin in human milk.
People who receive hemodialysis or peritoneal dialysis may
3
have an increased requirement for biotin, as may those with
genetic biotinidase deficiency.
Data were insufficient to set a UL.
3
The biotin content of foods is generally not documented. It is
3
widely distributed in natural foods, but its concentration varies.
Signs of biotin deficiency have been conclusively
3
demonstrated in individuals consuming raw egg whites over
long periods and in patients receiving total parenteral nutrition
(TPN) solutions that do not contain biotin.
The effects of biotin deficiency include dermatitis, alopecia,
3
conjunctivitis, and abnormalities of the central nervous system.
No adverse effects have been associated with high intakes of
3
biotin.

Biotin (vitamin H)

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Chemical structure and properties

Biotin was isolated in 1935 from egg yolk. Vitamin got its name from the Greek. bios is life because of its ability to stimulate the growth of yeast and bacteria.

The vitamin H molecule consists of imidazole and tetrahydrothiophene rings, the side chain is represented by valeric acid.

The N1-imidazole ring is the site of carboxylation. By binding to a bicarbonate ion (HCO3-), biotin becomes a coenzyme called carboxybiotin.

Biotin is able to form with avidin, a chicken egg protein glycoprotein, a strong complex that cannot be broken down by digestive enzymes. Therefore, with the private use of raw eggs, the absorption of biotin present in food stops. The ability of avidin and biotin molecules to specifically bind to each other is used in some purification methods in biotechnology.

Hypovitaminosis

Biotin hypovitaminosis is manifested by dermatitis, oily seborrhea, alopecia (focal alopecia), drowsiness, fatigue. Muscle pain is often noted.

Congenital disorders of biotin metabolism

The most common disorders associated with a defect in propionyl-CoA carboxylase and β-methylcrotonoyl-CoA carboxylase.

With a congenital defect of propionyl-CoA carboxylase, ketoacidosis is noted in the first weeks of a child’s life, attacks of which are provoked by feeding (food protein). Attacks are accompanied by frequent vomiting, muscle weakness, hypotension, drowsiness, dehydration and in most cases end in death. In a biochemical study, an increased concentration of propionic acid is detected in the blood, and long-chain ketones are detected in the urine. Excessive accumulation of propionic acid in tissues leads to the fact that it is included in the biosynthesis of fatty acids (instead of acetyl-CoA), while abnormal fatty acids with an odd number of carbon atoms are formed. Accumulating in brain phospholipids, such fatty acids cause severe neurological disorders.

Inhibition of the activity of β-crotonoyl-CoA-carboxylase leads to a violation of the breakdown of leucine at the stage of carboxylation of β-methylcrotonyl-CoA. With this congenital disorder, metabolic ketoacidosis develops. The disease manifests itself with indomitable vomiting, which does not stop after the patient switches to a low-protein diet. The condition improves after taking large doses of biotin.

Hypervitaminosis

Not described.

Food sources

Biotin is synthesized by the human intestinal microflora. This largely satisfies the body’s need for biotin. Taking antibiotics and treatment with cytostatics can lead to a hypovitaminosis state.

Vitamin H is rich in legumes, as well as cauliflower, mushrooms; from products of animal origin – liver, kidneys, milk, egg yolk.

Literature
T.S. Morozkina, A.G. Moiseyonok Vitamins. A short guide for doctors and students of medical, pharmaceutical and biological specialties.

Included in the following preparations:

Vitamin B7 – Biotin (Vitamin H, Vitamin B7, Biotin, Vitamin H)

Method of determination
HPLC-MS/MS (high performance liquid chromatography with tandem mass spectrometry).

Test material
Blood plasma (EDTA)

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Synonyms : Coenzyme R; Coenzyme R.

B7; Coenzyme R.

Brief characteristics of the analyte Vitamin B7 – biotin

Biotin – also known as vitamin B7 and vitamin H – a water-soluble vitamin of group B, is a cofactor of the five most important carboxylases involved in the synthesis and catabolism of fatty acids, amino acid metabolism, gluconeogenesis. The addition of biotin to these carboxylases is catalyzed by the enzyme Holocarboxylase synthetase (HLCS), while the enzyme biotinidase releases biotin from the breakdown products of carboxylase, making it available for a new cycle.

Good food sources of biotin are organ meats (liver, kidneys), eggs, yeast, milk. Grains, fruits, most vegetables, and meats contain less. Significant amounts of biotin can be synthesized by the human intestinal microflora.

Under what conditions can vitamin B7 deficiency develop in the body

Dietary deficiency of vitamin B7 and genetic defects in the enzymes involved in its metabolism (biotinidase, less commonly HLCS) can lead to a deficiency of biotin in the body. Lack of this vitamin in the body is observed infrequently.

Documented clinical cases have been described with long-term consumption of raw egg whites (which contain the biotin-binding protein avidin) or with almost exclusively parenteral nutrition without biotin supplementation, and in individuals with congenital disorders of its metabolism. Nutritional deficiency of the vitamin can be aggravated by the state of the microflora that produces biotin, for example, against the background of the use of antibiotics. A significant decrease in circulating biotin is noted in chronic alcoholism, in patients with achlorhydria, in old age, in people taking anticonvulsants. Mutations in the biotinidase gene disrupt the recycling (reuse) of biotin and lead to its increased loss in the urine (in the form complexed with peptides). Mutations of the HLCS gene with a decrease in the activity of this enzyme and metabolic disorders due to carboxylase deficiency with characteristic acidemia are rare.

How vitamin B7 deficiency can manifest itself in the body

Clinical manifestations of apparent biotin deficiency include anorexia, nausea, vomiting; glossitis; dermatitis; conjunctivitis; alopecia; ataxia; hypotension; ketolactacidosis/organic aciduria; convulsions; skin infections; thinning hair; rashes on the skin around the eyes, nose and mouth; impaired immune function; developmental delays in children.

When vitamin B7 preparations are used

Biotin is used in clinical practice to treat its deficiency in genetic disorders, high-dose supplements of this vitamin can be used in progressive multiple sclerosis (the mechanisms of its beneficial action in this pathology are still being established). Side effects of taking biotin in high doses (as observed in patients with biotinidase deficiency) are not described.

Biotin is gaining popularity and is being heavily promoted for its claimed effects on hair health and nail growth. Although the beneficial effect of this vitamin on hair and nails has indeed been established for individuals with an acquired or congenital deficiency of this vitamin, there is not enough evidence of its benefit for healthy people with a normal biotin status in the body.