Vitamin B7 (Biotin)
Also known as: Biotin, Vitamin H, Coenzyme R
Biotin serves as a critical coenzyme for four mammalian carboxylase enzymes: pyruvate carboxylase, acetyl-CoA carboxylase I and II, and propionyl-CoA carboxylase. These enzymes are essential for gluconeogenesis, fatty acid synthesis, and catabolism of branched-chain amino acids and odd-chain fatty acids. Biotin deficiency is rare but can manifest with dermatological, neurological, and metabolic symptoms. Supplementation in individuals with overt deficiency or genetic biotinidase deficiency can alleviate symptoms. However, therapeutic benefits in healthy individuals, particularly for dermatological improvements, are less robustly supported by evidence.
Last reviewed: 2026-04-22 · 3 indexed studies
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Overview
Biotin, also known as vitamin B7 or vitamin H, is a water-soluble vitamin that plays a crucial role in various metabolic processes, predominantly as a coenzyme for carboxylase enzymes. It is involved in fatty acid synthesis, gluconeogenesis, and amino acid metabolism. While often marketed for hair, skin, and nail health, the evidence supporting these benefits in non-deficient individuals is limited.
Mechanism & Function
Biotin · C₁₀H₁₆N₂O₃S — source: PubChem CID 171548
White crystalline B-vitamin. Tasteless; used at micro-gram doses.
- Capsule
- Tablet
- Gummy
- Liquid
Capsule is generally preferred for bioavailability or efficacy.
Mechanism of Action
Biotin functions as a covalently bound coenzyme for carboxylase enzymes, facilitating the transfer of carboxyl groups in various metabolic reactions. It is attached to the enzyme via a lysine residue. This carboxylation is vital for converting pyruvate to oxaloacetate (gluconeogenesis), acetyl-CoA to malonyl-CoA (fatty acid synthesis), and propionyl-CoA to methylmalonyl-CoA (amino acid and odd-chain fatty acid metabolism).
Physiological Role
Biotin's primary physiological role is to act as a coenzyme in fundamental metabolic pathways. It is essential for maintaining proper glucose homeostasis, lipid metabolism, and amino acid catabolism. It contributes to cellular energy production and the synthesis of macromolecules.
Primary Pathways
Performance / Health Relevance
Biotin's performance relevance is primarily indirect, through its role in energy metabolism. Optimal biotin levels support efficient carbohydrate, fat, and protein metabolism, which are crucial for energy production during exercise. However, there is no direct evidence suggesting biotin supplementation enhances athletic performance in individuals with adequate biotin status.
Evidence Review
Practical Use & Dosage
- Minimum Effective Dose
- 30 mcg/day (RDA)
- Optimal Range
- 30-10,000 mcg/day (therapeutic for genetic conditions)
- Upper / Caution Level
- No Upper Limit established, but dosages exceeding 10,000 mcg may interfere with lab tests.
- Timing
- Any time of day, with or without food.
- Best Format
- Oral capsules, tablets, or liquid drops.
- Bioavailability
- Highly bioavailable when orally administered. Absorption can be affected by avidin in raw egg whites.
- Absorption Considerations
- Absorbed in the small intestine via sodium-dependent multivitamin transporter (SMVT). Avidin in raw egg whites binds biotin, preventing absorption.
Safety & Interactions
Side Effects
- •Rare at typical doses; very high doses may interfere with lab tests (e.g., thyroid hormones, cardiac markers).
Contraindications
- Known hypersensitivity to biotin.
Drug Interactions
- •Anticonvulsants (carbamazepine, phenytoin, phenobarbital) may lower biotin levels.
- •Raw egg whites (contain avidin, which binds biotin).
Who Should Avoid
- •Individuals undergoing critical lab tests using streptavidin-biotin technology, especially at high doses.
Monitoring
Individuals on high-dose biotin should inform their healthcare providers, especially if lab tests are being performed, due to potential assay interference.
Frequently Asked Questions
Auto-generated from indexed evidence — dosage, safety, interactions, and more.
When is Vitamin B7 (Biotin) typically used or indicated?
Vitamin B7 (Biotin) is most commonly used for: Hair, Skin, and Nail Health, Metabolic Support, Blood Sugar Regulation. Biotin's primary physiological role is to act as a coenzyme in fundamental metabolic pathways. It is essential for maintaining proper glucose homeostasis, lipid metabolism, and amino acid catabolism. It contributes to cellular energy production and the synthesis of macromolecules.
How does Vitamin B7 (Biotin) work?
Biotin functions as a covalently bound coenzyme for carboxylase enzymes, facilitating the transfer of carboxyl groups in various metabolic reactions. It is attached to the enzyme via a lysine residue. This carboxylation is vital for converting pyruvate to oxaloacetate (gluconeogenesis), acetyl-CoA to malonyl-CoA (fatty acid synthesis), and propionyl-CoA to methylmalonyl-CoA (amino acid and odd-chain fatty acid metabolism).
What is the recommended dose of Vitamin B7 (Biotin)?
The optimal range is 30-10,000 mcg/day (therapeutic for genetic conditions). with a minimum effective dose of 30 mcg/day (RDA). Best taken: Any time of day, with or without food.. Upper / caution level: No Upper Limit established, but dosages exceeding 10,000 mcg may interfere with lab tests..
What are the side effects of Vitamin B7 (Biotin)?
Reported side effects include: Rare at typical doses; very high doses may interfere with lab tests (e.g., thyroid hormones, cardiac markers).. Monitoring: Individuals on high-dose biotin should inform their healthcare providers, especially if lab tests are being performed, due to potential assay interference.
Does Vitamin B7 (Biotin) interact with medications?
Known or theoretical interactions: Anticonvulsants (carbamazepine, phenytoin, phenobarbital) may lower biotin levels.; and Raw egg whites (contain avidin, which binds biotin).. Always check with a clinician before combining with prescription medication.
Who should avoid Vitamin B7 (Biotin)?
Vitamin B7 (Biotin) is generally not recommended for: Individuals undergoing critical lab tests using streptavidin-biotin technology, especially at high doses.; and Known hypersensitivity to biotin..
How strong is the evidence for Vitamin B7 (Biotin)?
Evidence level: Limited (overall score 45/100), based on 3 indexed studies on SuppIndex.
Research & References (3)
A double-blind, placebo-controlled study evaluating the efficacy of an oral supplement in improving hair, skin, and nail parameters.
This study investigated the effects of an oral supplement containing biotin and other nutrients on hair, skin, and nail health. While some improvements were observed generally in the group, the specific contribution of biotin beyond other ingredients was not isolated, and participants were not necessarily biotin deficient.
Biotin for the treatment of nail disease: A comprehensive update.
This systematic review examined the evidence for biotin supplementation in various nail conditions. The authors concluded that while some studies suggest a benefit for brittle nails, especially in individuals with actual biotin deficiency, the evidence in otherwise healthy individuals is less conclusive.
Biotin interference with immunoassays: A multidisciplinary approach from laboratory implications to clinical management.
This review focused on the significant issue of high-dose biotin supplementation interfering with a wide range of laboratory immunoassays, leading to potentially misleading results for thyroid function tests, cardiac biomarkers, and hormone levels.
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Research Overview
Limited EvidenceCite this ingredient
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Stable URL
https://thesuppindex.com/ingredients/vitamin-b7-biotin
SuppIndex. (2026). Vitamin B7 (Biotin): Evidence summary, dosage and clinical studies. Retrieved October 23, 2026, from https://thesuppindex.com/ingredients/vitamin-b7-biotin
Based on 3 indexed studies · Evidence level: Limited.
Goal Ratings
Stack Compatibility
Generally safe to stack with other vitamins and minerals. No known adverse interactions with common supplements, aside from potential lab test interference at high doses.