Vitamin B7
Biotin
Water-soluble vitamins
Aliases / common names
Biotin; vitamin H; coenzyme R
Natural food sources
Egg yolk, liver, salmon, pork, nuts, seeds and some vegetables.
Main wellness functions
Coenzyme for carboxylases; supports fatty-acid, glucose and amino-acid metabolism.
Deficiency signs
Hair thinning, brittle nails, dermatitis, conjunctivitis, depression, lethargy and neurologic symptoms.
Recommended intake
AI adults: 30 mcg/day. Children: about 8-25 mcg/day. Pregnancy: 30 mcg/day. No established UL.
Excess intake effects
No clear toxicity, but high-dose biotin can interfere with many immunoassay blood tests.
Contraindicated / caution groups
People undergoing thyroid, cardiac troponin, hormone or pregnancy-related lab tests should disclose biotin use.
Common dosage forms
Tablets, capsules, gummies, hair-skin-nails formulas.
Common product strengths
30-300 mcg in multivitamins; 1,000-10,000 mcg in beauty products.
Use precautions
Stop or disclose high-dose biotin before lab testing according to clinician/lab instructions.
Supplement notes
Evidence for hair/nail benefit is strongest when deficiency or brittle nail conditions exist.
This information is for general nutrition education and product reference only. It does not replace medical diagnosis, treatment or individualized dietary advice.