Vitamin B7

• Metabolic health
• Glucose regulation
• Cellular energy production
• Gene regulation

• Hair health
• Skin health
• Nail strength
• Nervous system function
• Cognitive health
• Embryonic development

Biotin functions primarily as an essential cofactor for five carboxylase enzymes that catalyze critical steps in metabolism. These enzymes include pyruvate carboxylase (involved in gluconeogenesis), acetyl-CoA carboxylase 1 and 2 (involved in fatty acid synthesis and regulation), propionyl-CoA carboxylase, and 3-methylcrotonyl-CoA carboxylase (both involved in amino acid metabolism). Through these carboxylase enzymes, biotin plays crucial roles in glucose production, fatty acid synthesis and oxidation, and the metabolism of branched-chain amino acids. Biotin is covalently bound to these enzymes through the action of holocarboxylase synthetase, forming biocytin.

Beyond its role as a cofactor, biotin influences gene expression through biotinylation of histones, affecting chromatin structure and DNA repair mechanisms. This epigenetic function may explain some of biotin’s effects on cellular development and differentiation. Additionally, biotin appears to enhance insulin sensitivity and glucose utilization, potentially through effects on pancreatic beta-cell function and glucose metabolism pathways. It also supports thyroid and adrenal function, influences immune system activity, and contributes to nervous system health through its role in myelin synthesis.

Through these diverse mechanisms, biotin affects energy production, macronutrient metabolism, and cellular signaling pathways that influence overall health and longevity.

The Adequate Intake (AI) for biotin is 30 mcg per day for adults. However, for therapeutic purposes, doses ranging from 300-10,000 mcg (0.3-10 mg) are commonly used. For general health support, 100-300 mcg daily is typical. For specific conditions like brittle nails or hair loss, higher doses of 1,000-10,000 mcg daily have been studied, though evidence for efficacy at these doses is mixed.

Upper Limit: No established Tolerable Upper Intake Level (UL)

High Dose Considerations: Doses up to 200,000 mcg/day have been used for biotinidase deficiency without significant adverse effects

Laboratory Interference: Biotin supplements can significantly interfere with many laboratory tests; discontinue at least 72 hours before blood work

Pregnancy Safety: Generally considered safe; high doses should be used under healthcare supervision

Contraindications: No significant contraindications at recommended doses

Biotin is absorbed primarily in the small intestine through a carrier-mediated process that becomes saturated at higher doses. At typical dietary and supplement doses, absorption efficiency is approximately 50-60%. Free biotin is readily absorbed, while biotin bound to proteins in food must first be cleaved by biotinidase, an enzyme in the intestinal tract. Once absorbed, biotin is transported in the bloodstream, with about 81% bound to plasma proteins.

Biotin crosses the blood-brain barrier and is distributed to various tissues, with highest concentrations in the liver, kidneys, and brain. Excess biotin is excreted in urine, with small amounts appearing in bile.

Taking with food may enhance absorption of some forms, Dividing larger doses may improve overall absorption, Ensuring adequate biotinidase activity (genetic testing for deficiency), Supporting gut health for optimal microbiome-produced biotin, Avoiding raw egg whites, which contain avidin that binds biotin, Liposomal formulations may theoretically enhance cellular delivery (limited research)

For general supplementation, biotin can be taken at any time of day, with or without food. There is no strong evidence that timing significantly affects the efficacy of biotin for most purposes. For those taking higher doses (above 300 mcg), dividing the dose throughout the day may theoretically improve overall absorption by preventing saturation of transport mechanisms, though clinical evidence for this approach is limited. For those taking multiple supplements, biotin can generally be taken alongside other water-soluble vitamins without interference.

Consistency in daily supplementation is generally more important than specific timing for achieving desired effects on hair, skin, and nails, which typically require 3-6 months of regular use to show improvement.

For most healthy individuals, standard biotin supplements (30-300 mcg) are adequately absorbed, For higher doses (1,000+ mcg), dividing throughout the day may theoretically improve absorption, Avoid taking biotin with raw egg whites, which contain avidin that binds biotin, Support gut health for optimal microbiome-produced biotin, Be aware that biotin supplements can significantly interfere with many laboratory tests; discontinue at least 72 hours before blood work, For hair, skin, and nail benefits, consistent daily supplementation for 3-6 months is typically needed, Topical biotin products have limited evidence for efficacy due to poor penetration, Those on long-term anticonvulsants or antibiotics may need higher biotin doses, Individuals with inflammatory bowel conditions may require higher doses due to reduced absorption, Consider genetic testing for biotinidase deficiency if there are unexplained neurological symptoms or persistent skin issues

Biotin has an exceptional safety profile, even at doses many times higher than the Adequate Intake (AI) of 30 mcg/day. No Tolerable Upper Intake Level (UL) has been established due to the lack of observed adverse effects at high doses. Doses up to 200,000 mcg/day have been used in treating biotinidase deficiency without significant adverse effects.

The most significant concern with biotin supplementation is not related to toxicity but rather to its interference with numerous laboratory tests, which can lead to misdiagnosis and inappropriate treatment if healthcare providers are unaware of biotin use.

No Tolerable Upper Intake Level (UL) has been established for biotin, as no adverse effects have been associated with high oral intakes from food or supplements. Doses up to 200,000 mcg/day (200 mg/day) have been used in treating biotinidase deficiency without significant adverse effects. The body efficiently eliminates excess biotin through the urine. As with any supplement,

it ‘s prudent to use the lowest effective dose for the intended purpose, but biotin is generally considered one of the safest vitamins even at high doses.

Children:

• Excellent safety record
• Doses should be adjusted based on age and weight
• High doses used safely in children with biotinidase deficiency

Pregnant Women:

• Generally considered safe at recommended doses
• Adequate biotin is important for fetal development
• No evidence of adverse effects at typical supplemental doses

Breastfeeding Women:

• Generally considered safe at recommended doses
• Biotin is secreted in breast milk
• No evidence of adverse effects on nursing infants

Older Adults:

• Excellent safety profile
• No special concerns; may benefit from slightly higher doses
• No evidence of increased sensitivity to adverse effects

Acute Toxicity: Extremely low acute toxicity; no known cases of serious overdose

Symptoms Of Excessive Intake: No well-documented symptoms of biotin overdose

Management: No specific management needed; discontinuation sufficient

Antidote: None required; elimination through urine

Chronic High Dose Effects: No known adverse effects from long-term high-dose use

Monitoring Recommendations: No specific monitoring needed for safety reasons

Evidence From Clinical Trials: Long-term high-dose therapy for biotinidase deficiency shows excellent safety profile

Mechanism: Biotin interferes with biotin-streptavidin technology used in many immunoassays

Affected Tests:

• Thyroid function tests (TSH, T3, T4)
• Cardiac markers (troponin)
• Hormone tests (estradiol, testosterone, progesterone)
• Vitamin D levels
• Cancer markers (PSA, CA-125)
• Many other immunoassay-based tests

Potential Consequences: False high or low results leading to misdiagnosis and inappropriate treatment

Recommendations: Discontinue biotin supplementation at least 72 hours before laboratory testing

Dose Relationship: Interference more likely with doses ≥5,000 mcg/day, but possible with lower doses

Inform healthcare providers about biotin supplementation, especially before laboratory testing, Discontinue biotin at least 72 hours before scheduled laboratory tests, Start with lower doses and increase gradually if needed, Take with food if gastrointestinal discomfort occurs, Be aware that very high doses (≥10,000 mcg/day) are rarely necessary except for specific medical conditions, Monitor for potential interactions if taking anticonvulsant medications, Consider the potential impact on laboratory test results when evaluating the risk-benefit ratio of high-dose supplementation, For hair, skin, and nail benefits, moderate doses (300-1,000 mcg) are typically sufficient, Pregnant women should consult healthcare providers before taking doses significantly above the AI, Remember that more is not necessarily better; use the lowest effective dose for your specific needs

Biotin is recognized as Generally Recognized as Safe (GRAS) by the FDA. It is approved as a nutrient supplement and food additive. The FDA has established a Reference Daily Intake (RDI) of 30 mcg for adults, which is used for nutrition labeling purposes. In 2017 and 2019, the FDA issued safety communications about biotin’s interference with laboratory tests, warning that high doses can cause clinically significant incorrect test results.

These communications were intended to increase awareness among healthcare providers and patients but did not change biotin’s regulatory status as a dietary supplement.

Us: No Tolerable Upper Intake Level (UL) established due to lack of observed adverse effects

Eu: No UL established; EFSA concluded insufficient data to establish UL

Australia: No UL established; considered to have low toxicity

Special Considerations: Despite no established UL, regulatory bodies generally recommend using the lowest effective dose for the intended purpose

Increasing focus on biotin’s interference with laboratory tests may lead to additional labeling requirements or warnings, Growing scrutiny of beauty-related claims for supplements may impact permitted marketing language for biotin products, Harmonization efforts between major regulatory bodies may lead to more consistent international standards, Potential development of specific guidance for high-dose biotin products that substantially exceed nutritional requirements, Increased monitoring of adverse event reporting related to biotin, particularly regarding misdiagnosis due to laboratory interference

Low to moderate, with significant variation between doses

Focus on overall diet quality first; many people get sufficient biotin from food, Consider testing for biotin deficiency before investing in high-dose supplements, For hair and nail concerns, give supplements at least 3-6 months to show effects, Remember that more expensive doesn’t necessarily mean better quality, Consider combination products only if you need the additional ingredients, Be wary of dramatic before/after marketing images for beauty supplements, For general health, lower doses (30-300 mcg) are typically sufficient, Discontinue use if no benefits are observed after 3-6 months, Remember to factor in the cost of laboratory test interference (potentially requiring test repetition), Consider the environmental and ethical aspects of production as part of overall value assessment

Biotin supplements typically have a shelf life of 2-3 years when properly stored. Biotin is relatively stable compared to some other B vitamins, particularly in dry form. Liquid formulations generally have shorter shelf lives due to potential degradation in solution. The shelf life indicated on commercial products assumes storage under recommended conditions.

Store biotin supplements in a cool, dry place away from direct light and heat. The ideal temperature range is 59-77°F (15-25°C). Refrigeration is not necessary for dry forms but may extend the shelf life of liquid formulations. Keep containers tightly closed to prevent moisture exposure, as humidity can accelerate degradation. Avoid storing in bathrooms or kitchens where temperature and humidity fluctuations are common.

Analytical Methods: High-Performance Liquid Chromatography (HPLC), Microbiological assays, Mass spectrometry, Bioassays measuring carboxylase activity

Visual Indicators: Pure biotin is a white crystalline powder; yellowing may indicate degradation. In supplements, changes in color, smell, or texture may indicate degradation or contamination.

Stability Testing Protocols: Accelerated stability testing exposes products to elevated temperatures and humidity to predict long-term stability. Real-time stability testing monitors products under normal storage conditions over their intended shelf life.

Follow storage instructions on the product label, Keep supplements in their original containers with desiccants if provided, Avoid transferring to containers that don’t seal properly, Don’t store different supplements in the same container, Discard supplements that have changed in appearance, smell, or taste, Note the expiration date when purchasing and discard expired products, If traveling to humid or hot climates, take special precautions to protect supplements, For liquid formulations, refrigerate after opening if recommended, Keep supplements out of reach of children, who may leave containers open, Consider smaller package sizes if you don’t use supplements quickly

Debug Information:

Section: testing_methods

Data type: array

Array keys: testing_methods

testing_methods key exists with type: array

spp_render_generic_fields function exists: Yes

• Serum or plasma biotin levels (direct measurement, not commonly available in clinical settings)
• Urinary biotin excretion
• Functional testing of biotin-dependent carboxylase activities
• Biotinidase activity (to assess the enzyme that releases protein-bound biotin)
• Clinical assessment of signs and symptoms of deficiency

Synthesis Methods

Natural Sources

Intestinal Synthesis

Commercial Forms

Quality Considerations

Sustainability Considerations

Initial Discovery: Biotin was first discovered in 1927 by Margaret Averil Boas (later Margaret Dann) during her research on nutritional deficiencies in rats. She observed that rats fed a diet of raw egg whites developed a syndrome characterized by dermatitis, hair loss, and neurological symptoms.

Naming History: The substance was initially called ‘Protective Factor X’ and later ‘vitamin H’ (from the German word ‘Haut,’ meaning skin) due to its effects on skin health. The name ‘biotin’ was derived from the Greek word ‘biotos,’ meaning ‘life’ or ‘sustenance.’

Isolation: In 1940, Vincent du Vigneaud successfully isolated biotin from egg yolk. Paul Győrgy confirmed that vitamin H and the ‘coenzyme R’ isolated from liver were identical to biotin.

Structure Determination: The chemical structure of biotin was determined in 1942 by Fritz Kögl and Benno Tönnis. The complete stereochemical structure was later confirmed by X-ray crystallography.

Deficiency Studies: Early research focused on the ‘egg white injury’ phenomenon, where animals fed raw egg whites developed deficiency symptoms due to avidin binding biotin. This led to the recognition of biotin as an essential nutrient.

Metabolic Role Discovery: In the 1950s and 1960s, research established biotin’s role as a cofactor for carboxylase enzymes, revealing its critical importance in metabolism.

Human Deficiency Recognition: Human biotin deficiency was first clearly described in the 1940s, often occurring in individuals consuming large amounts of raw egg whites or in those receiving total parenteral nutrition without biotin supplementation.

Traditional Applications: Before its identification as a vitamin, foods rich in biotin (such as liver and egg yolks) were traditionally used in various cultures to treat skin conditions and promote hair growth.

Early Medical Applications: Following its discovery, biotin was first used medically to treat dermatitis and hair loss associated with deficiency states.

Pediatric Applications: Biotin has been used since the 1970s to treat seborrheic dermatitis in infants, a condition that sometimes responds to biotin supplementation.

Genetic Disorder Treatment: Since the identification of biotinidase deficiency and multiple carboxylase deficiency, high-dose biotin has been the standard treatment for these genetic disorders, preventing severe neurological and developmental consequences.

Early Supplements: Biotin was initially available primarily as a prescription item for treating deficiency. Early supplements were typically low-dose and often combined with other B vitamins.

Beauty Supplement Emergence: In the 1970s and 1980s, biotin began to gain popularity as a supplement for hair and nail health, though evidence for its effectiveness in non-deficient individuals remained limited.

High Dose Trend: The 1990s and 2000s saw a trend toward higher-dose biotin supplements (1,000-10,000 mcg) marketed specifically for beauty benefits, despite limited clinical evidence supporting these doses for cosmetic purposes.

Modern Formulations: Contemporary biotin supplements include various delivery forms (capsules, gummies, liquids) and are often combined with collagen, silica, and other nutrients in beauty formulations.

Initial Focus: Early research focused on identifying biotin’s structure and basic metabolic functions as a carboxylase cofactor.

Metabolic Investigations: Mid-20th century research established biotin’s critical roles in glucose, fatty acid, and amino acid metabolism.

Genetic Disorder Research: The 1970s and 1980s saw significant advances in understanding genetic disorders of biotin metabolism, leading to effective treatments and screening programs.

Epigenetic Discoveries: More recent research has revealed biotin’s role in gene regulation through histone biotinylation, expanding understanding beyond its classical role as a metabolic cofactor.

Current Research Areas: Contemporary research focuses on biotin’s potential roles in glucose metabolism, immune function, and neurological health, as well as addressing the widespread use of biotin for hair, skin, and nail health.

Beauty Industry Impact: Biotin has become a staple ingredient in beauty supplements, with marketing often emphasizing its benefits for hair, skin, and nails despite variable clinical evidence.

Popular Perception: In popular culture, biotin has gained recognition as the ‘hair and nail vitamin,’ with widespread belief in its cosmetic benefits driving significant consumer demand.

Market Evolution: The biotin supplement market has grown substantially since the 1990s, with particular acceleration in the 2010s as part of the broader beauty-from-within trend.

Regulatory Developments: Increasing recognition of biotin’s interference with laboratory tests led to FDA warnings in 2017 and 2019, raising awareness of this previously underappreciated issue.

The discovery of biotin through egg white injury demonstrates how naturally occurring substances (avidin) can reveal essential nutrients, Biotin’s history illustrates the progression from identifying deficiency symptoms to understanding molecular mechanisms, The gap between biotin’s established metabolic roles and its popular use for beauty highlights the common disconnect between scientific evidence and consumer trends, The relatively recent discovery of biotin’s interference with laboratory tests reminds us that even well-studied nutrients can have unexpected effects, Biotin’s successful use in treating genetic disorders demonstrates the importance of understanding nutrient metabolism for developing targeted therapies

Biotin has strong evidence supporting its essential role in human metabolism and the treatment of biotinidase deficiency, a rare genetic disorder. However, evidence for its popular applications in improving hair, skin, and nail health is surprisingly limited and of variable quality. Most studies are small, lack proper controls, or have methodological limitations. Evidence for biotin’s role in glucose metabolism and diabetes is emerging but preliminary.

The strongest evidence exists for the treatment of biotin-responsive genetic disorders and certain rare forms of hair loss associated with biotin deficiency.

Despite widespread marketing, evidence for biotin’s benefits for hair, skin, and nails in non-deficient individuals is limited, Individuals with risk factors for deficiency (pregnancy, anticonvulsant use, malabsorption, etc.) may be more likely to benefit, For nail brittleness, evidence is slightly stronger than for hair loss, Effects on hair and nails, if present, typically take 3-6 months to become apparent, Higher doses (>1,000 mcg) have not shown proportionally greater benefits for cosmetic applications, Biotin is clearly effective for treating deficiency states and genetic disorders affecting biotin metabolism, Emerging evidence suggests potential benefits for glucose metabolism, but more research is needed, Laboratory test interference is a significant concern with high-dose supplementation, The excellent safety profile makes a trial of supplementation reasonable for those seeking hair, skin, and nail benefits, Consider testing for biotin deficiency before supplementation, particularly in cases of unexplained hair loss