Recommended Daily Intake for Biotin
Adults need 30 micrograms (mcg) of biotin daily, according to the National Institutes of Health (NIH). This meets requirements for most people through diet alone—sources include eggs, nuts, salmon, and avocados.[1]
Dosing for Deficiency or Hair/Nail Support
For biotin deficiency (rare, often linked to genetic issues, pregnancy, or alcoholism), doses range from 10 mg (10,000 mcg) to 20 mg daily, sometimes higher under medical supervision. Supplements for hair growth or brittle nails commonly use 2.5 mg to 10 mg daily, though evidence is limited to small studies showing modest benefits.[1][2]
High-Dose Uses in Medical Conditions
In multiple sclerosis (MS) treatment with high-dose biotin (HD-Biotin), protocols like MD1003 use 300 mg daily, split into three 100 mg doses. This targets progressive MS but lacks FDA approval and shows mixed trial results.[3] For unapproved uses like diabetic neuropathy, doses up to 100 mg daily appear in studies.
Safety and Upper Limits
No established upper intake level exists due to biotin's low toxicity—doses up to 10 mg daily are safe for adults, with rare side effects like nausea or skin rash at extremes. It can interfere with lab tests (e.g., thyroid or troponin), so inform doctors before high doses.[1][2]
Who Should Adjust Dosing
Pregnant or breastfeeding people: 30-35 mcg daily. Children: 5-20 mcg based on age. Those with kidney issues or on anticonvulsants may need more due to impaired absorption.[1]
Sources
[1]: NIH Biotin Fact Sheet
[2]: Mayo Clinic Biotin Overview
[3]: Medscape High-Dose Biotin in MS