Biotin

Introduction Overview

Generic Name

biotin

Brand Name

Appearex, Cyto B7, Hair, Skin, Nails, Spring Valley Biotin Gummies, Vitafusion Biotin Extra Strength Gummy, Biotin High Potency Gummies

Dosage Form

oral capsule, oral liquid, oral tablet, oral chewable tablet, oral disintegrating tablet

Drug Class

Vitamins

Pharmacokinetics

Absorption

Biotin is absorbed primarily in the jejunum and ileum of the small intestine through a sodium-dependent multivitamin transporter (SMVT). Absorption is efficient at physiological doses but may be saturable at very high supplemental doses. The bioavailability of orally administered biotin is generally high; however, simultaneously ingesting raw egg whites over prolonged periods can inhibit absorption due to avidin binding to biotin, preventing its uptake. Clinical factors affecting absorption include gastrointestinal diseases that impair nutrient absorption and drug interactions that modulate transporter activity.

Distribution

After absorption, biotin is distributed widely throughout body tissues, demonstrating preferential accumulation in the liver, kidneys, and adrenal glands, reflecting its role as a coenzyme in metabolic pathways. Plasma biotin circulates primarily bound to serum albumin and other proteins, facilitating delivery to target tissues. Biotin distribution is relatively rapid, with tissue uptake allowing participation in carboxylation reactions essential for fatty acid synthesis, gluconeogenesis, and amino acid catabolism.

Metabolism

Biotin undergoes minimal metabolism; it mostly circulates in its free form or as biotinylated carboxylases. Biotin is covalently bound to the apoenzyme subunits of carboxylase enzymes, activating these enzymes to catalyze critical metabolic processes. Excess biotin not utilized for enzyme biotinylation can be converted to biotin metabolites such as bisnorbiotin and tetranorbiotin, which are excreted in urine. Metabolic pathways ensure recycling and homeostasis of this vitamin under normal physiological conditions.

Elimination

Biotin and its metabolites are primarily eliminated via renal excretion. The kidneys filter free biotin and its metabolites, which may undergo tubular reabsorption to a limited extent. Renal clearance of biotin increases with higher plasma concentrations. In patients with compromised renal function, biotin clearance may be reduced, leading to increased systemic levels. Biotin has a relatively short half-life, estimated around several hours, supporting the necessity for regular dietary intake or supplementation to maintain adequate levels.

Dosage Forms

Adults

Biotin is commonly available in multiple oral formulations for adults including capsules (10000 mcg, 5 mg, 5000 mcg), oral liquids (5 mg/mL), tablets (10 mg, 1000 mcg, 2.5 mg, 300 mcg), chewable tablets (2500 mcg, 5000 mcg), and disintegrating tablets (10000 mcg, 5000 mcg). Typical dosing ranges from daily supplementation of 30 mcg to therapeutic doses up to 10 mg or more depending on clinical indication, with higher doses often used in metabolic disorders or biotin deficiency states. Administration should be consistent with healthcare provider instructions, and doses should not exceed recommended amounts to avoid potential interference with laboratory assays or toxicity concerns.

Adolescents

For adolescents, biotin supplementation is typically dosed similarly to adults for deficiency treatment or supplementation - commonly between 30 mcg to 5 mg daily. Pediatric formulations such as chewable tablets and liquids facilitate administration. Dosing may be weight-based or adjusted according to medical condition and under professional supervision. Careful monitoring is recommended, especially in those with metabolic conditions or on concomitant medications that may affect biotin levels.

Special Populations

In individuals with biotinidase deficiency, higher doses are required and lifelong supplementation is necessary. Patients with renal impairment or those on dialysis may require dose adjustments due to altered clearance; consultation with a healthcare provider is essential. Pregnant and breastfeeding women should consult providers before use, as established safe dosing protocols are limited. Additionally, smokers may have altered biotin requirements. Children should use biotin under medical supervision to avoid overdose. Caution is advised in patients taking anticonvulsants such as carbamazepine, phenytoin, and phenobarbital, which can reduce biotin plasma levels.

Mechanism Of Action

Biotin functions primarily as a water-soluble B-vitamin (Vitamin B7) essential as a coenzyme for carboxylase enzymes involved in key metabolic pathways. It covalently binds to apocarboxylase enzymes, converting them to their active holoenzyme forms necessary for catalyzing carboxylation reactions. These enzymes include acetyl-CoA carboxylase (crucial in fatty acid synthesis), pyruvate carboxylase (gluconeogenesis), propionyl-CoA carboxylase (amino acid catabolism), and β-methylcrotonyl-CoA carboxylase (leucine catabolism). By serving as a coenzyme, biotin facilitates the transfer of activated carbon dioxide to substrates via the carboxylase enzymes, playing a vital role in energy metabolism and biosynthetic processes.

Pharmacological Actions

Coenzyme for carboxylase enzymes facilitating fatty acid synthesis and gluconeogenesis.
Promotes metabolism of carbohydrates, fats, and amino acids to generate energy.
Supports gene expression regulation and cellular signaling pathways related to metabolism.
Enhances keratin infrastructure, benefiting hair, skin, and nail integrity.
Potential neuromodulatory function implicated in nervous system maintenance.
Involved in histone biotinylation affecting chromatin structure and gene regulation.
May modulate inflammatory responses through metabolic effects.
Facilitates metabolic homeostasis in various tissues.
Supports normal embryonic growth and development through metabolic support.
Contributes to maintenance of mucous membranes and epithelial integrity.

Therapeutic Clinical Uses

Treatment and prevention of biotin deficiency due to malnutrition, genetic deficiency (biotinidase deficiency), or long-term tube feeding.
Dietary supplementation to ensure adequate biotin levels in at-risk populations.
Adjunctive therapy aimed at promoting healthy hair, skin, and nails although evidence is limited and largely anecdotal.
Investigational use in multiple sclerosis symptoms, though clinical evidence does not conclusively support efficacy.
Management of seborrhea in infants as part of supportive care.
Supportive nutritional therapy in metabolic disorders involving carboxylase deficiencies.
Use in certain neurodegenerative or neuropathic conditions under research.
May be used along with other vitamins for general health supplementation.
Treatment in conditions where biotin absorption is compromised due to medical conditions or drug use.
Potential off-label use for brittle nails and hair loss, lacking robust clinical validation.

Side Or Adverse Effects

Allergic reactions including rash, hives, swelling, and difficulty breathing, though rare.
Mild gastrointestinal disturbances such as diarrhea and upset stomach.
Respiratory problems like nasal congestion or cough reported infrequently.
False positive or false negative results in certain laboratory tests, such as thyroid function tests and troponin assays, complicating clinical interpretation.
Potential interaction with laboratory diagnostic tests leading to misdiagnosis if not recognized.
Very high doses may cause skin rash in sensitive individuals.
There is limited evidence of neurotoxicity or toxicity at standard doses given biotin's water-soluble nature.
No well-established teratogenic effects, but caution advised in pregnancy.
Minimal drug toxicity observed at normal supplementation doses.
In rare cases, oversupplementation may lead to imbalance of other B-vitamin levels.

Precautions

Inform healthcare providers about all medications and supplements being taken to avoid interactions.
Do not exceed recommended daily doses without medical advice to prevent potential assay interference.
Use with caution in patients with known enzyme deficiencies such as biotinidase deficiency.
Discontinue use if allergic symptoms or hypersensitivity reactions occur.
Advise patients to disclose biotin use prior to laboratory testing to avoid erroneous results.
Careful use in patients with kidney disease due to altered elimination.
Avoid simultaneous use of different biotin formulations to prevent overdose.
Instruct patients on proper measurement when using liquid formulations to ensure accurate dosing.
Exercise caution in pregnant or breastfeeding women; consult healthcare providers before use.
Avoid in individuals with known hypersensitivity to biotin or components of the formulation.
Use under medical supervision in pediatric populations.

Warnings

Do not use in individuals allergic to biotin or any formulation ingredients.
High-dose supplementation can interfere with diagnostic laboratory tests, potentially causing misdiagnosis or inappropriate treatment.
Use caution in patients with kidney impairment or on dialysis, as altered biotin clearance may occur.
Avoid giving supplements to children without medical advice due to dosing and safety considerations.
Not approved by the FDA for treatment of any diseases; use only as dietary supplement or under physician guidance.
Potential for false laboratory test results necessitates disclosure to healthcare providers and laboratories.
Avoid self-medication for serious conditions; biotin should not replace prescribed drugs.
Ensure use of reliable, contamination-free products because some supplements may contain toxic impurities.
Use according to labeled instructions to reduce risk of overdose or adverse effects.
Patients should report any unexpected symptoms or adverse reactions promptly.

Contraindications

Known hypersensitivity or allergy to biotin.
Use should be avoided if the patient has demonstrated allergy to any component in the formulation.
No absolute contraindications identified beyond allergic reactions, but use should be cautious in conditions with altered metabolism or elimination until supervised by healthcare provider.
Not intended as a substitute for medically prescribed treatments; contraindicated as monotherapy in diseases without proven benefit.
Avoid use in pediatric patients without medical supervision.

Drug Interactions

Anticonvulsant medications such as carbamazepine, phenytoin, phenobarbital, and primidone can reduce biotin serum concentrations.
Concomitant use with these anticonvulsants may necessitate higher biotin doses to maintain adequate levels.
High biotin intake can interfere with immunoassays, including thyroid function tests, troponin, and other diagnostic assays, leading to false results.
No significant interactions with food reported, but raw egg white consumption decreases biotin absorption significantly due to avidin binding.
Potential interaction with other vitamin or mineral supplements should be assessed to avoid redundancy or imbalance.
Drugs that alter gastrointestinal pH or motility may modify biotin absorption rates.
Interactions with herbal supplements are not well studied but possible; caution advised with polypharmacy.
No significant cytochrome P450 interactions identified as biotin is not metabolized via these pathways.
Possible effects on laboratory test interpretation rather than direct pharmacodynamic interactions.
Other drugs reducing intestinal absorption or increasing elimination might reduce biotin levels.

Preparations Of The Drug

Oral capsules available in 10000 mcg (10 mg), 5 mg, and 5000 mcg (5 mg) strengths.
Oral liquids formulated at 5 mg/mL concentration with included measuring device for accuracy.
Standard oral tablets available in doses of 10 mg, 1000 mcg (1 mg), 2.5 mg, and 300 mcg.
Chewable oral tablets provided at 2500 mcg (2.5 mg) and 5000 mcg (5 mg) dosages.
Orally disintegrating tablets enabling sublingual or buccal absorption at 10000 mcg (10 mg) and 5000 mcg (5 mg).
Preparations intended for both supplementation and therapeutic use depending on dose.
Multi-vitamin combinations containing biotin are commonly used for broad nutritional supplementation.
Available as gummy formulations marketed for hair, skin, and nail health.
Supplement forms sold under multiple brand names including Appearex, Cyto B7, and several over-the-counter dietary supplement brands.
Products vary in dose concentrations to accommodate different therapeutic or dietary goals.