Vitamins
Biotin (Vitamin B7)
Also known as: Vitamin H · Vitamin B7 · Coenzyme R
A co-factor for carboxylase enzymes essential to fatty acid synthesis and gluconeogenesis. Most 'hair and nail' claims are overstated in non-deficient individuals — deficiency is rare.
Effective Dose
30–10000mcg / day
per clinical evidence
Evidence Level
Moderate
Vitamins
Mechanism
Carboxylase co-factor — fatty acid synthesis, gluconeogenesis, amino acid catabolism
primary action
Best For
Hair and nail health
Glucose metabolism, Deficiency correction
This profile is for informational purposes only and does not constitute medical advice. Consult a qualified healthcare professional before starting any supplementation, especially if you have pre-existing conditions or take medications.
What Is Biotin (Vitamin B7)?
Biotin is required as a prosthetic group for four carboxylase enzymes: acetyl-CoA carboxylase (fatty acid synthesis), pyruvate carboxylase (gluconeogenesis), propionyl-CoA carboxylase (odd-chain fatty acid metabolism), and 3-methylcrotonyl-CoA carboxylase (leucine catabolism). True deficiency is rare but does cause hair loss and dermatitis.
How It Works: The Science
Biotin is covalently attached to carboxylase enzymes via biotinidase, enabling CO₂ transfer in carboxylation reactions. Avidin in raw egg whites binds biotin with extraordinary affinity, causing deficiency in those consuming large amounts of raw eggs. High-dose biotin supplementation interferes with immunoassay-based laboratory tests (troponin, thyroid hormones) — important clinical caveat.
Primary Mechanism
Carboxylase co-factor — fatty acid synthesis, gluconeogenesis, amino acid catabolism
Evidence-Based Benefits
Dosage Guide
Effective Dose
30–10000mcg / day
AI: 30mcg/day (easily met from food). Hair/nail claims use 2.5–10mg/day. Caution: high-dose biotin (>5mg/day) can cause false positives or negatives in laboratory tests (troponin, TSH, hCG) — inform your doctor.
Safety Profile & Side Effects
No established UL — water-soluble and excreted readily. Laboratory interference is the primary safety concern at high doses. Not toxic at commonly supplemented doses.
Who Should (and Shouldn't) Take It
Genuinely deficient individuals (rare). Most hair supplement claims are unsupported in non-deficient people. Raw egg white consumers should supplement. Inform healthcare providers if taking >1mg/day before laboratory tests.
Frequently Asked Questions
Related Ingredients
Medical Disclaimer
Ingredient profiles are for informational purposes only and do not constitute medical advice. Consult a qualified healthcare professional before starting any supplementation, especially if you have pre-existing conditions or take medications. Full disclaimer →