Biotin | whatsinit

About

What it is and where it shows up.

Biotin is a water-soluble B-vitamin (B7) that serves as an essential cofactor for carboxylase enzymes involved in fatty acid synthesis, gluconeogenesis, and branched-chain amino acid catabolism. It is naturally present in a wide variety of foods including eggs, liver, nuts, seeds, and dairy, and is also added to fortified foods and dietary supplements.

Safety summary

The regulatory and scientific consensus.

Biotin is considered a safe, non-toxic vitamin that the body excretes in urine when in excess, and no Tolerable Upper Intake Level has been established by EFSA or the US FNB due to absence of adverse effects at high dietary intakes. However, high-dose supplementation (generally >1 mg/day) is a recognised patient-safety risk because excess circulating biotin interferes with biotin-streptavidin immunoassays, producing falsely low or falsely high results for critical tests including thyroid hormones, troponin, and parathyroid hormone. Individuals with epilepsy taking anticonvulsants may have depleted biotin status due to increased catabolism, while those with diabetes should exercise caution as excess biotin may affect postprandial glucose control.

Regulatory landscape

What food-safety regulators have decided.

Jurisdiction	Status	Note
EFSA (European Food Safety Authority) (European Union)	Approved	Adequate Intake (AI) of 40 µg/day established for adults; AI of 40 µg/day also proposed for pregnant women and 45 µg/day for lactating women; no Tolerable Upper Intake Level established due to insufficient evidence of adverse effects. Health claims approved under EU Regulation 432/2012 covering normal hair, skin, mucous membranes, macronutrient metabolism, psychological function, and reduction of tiredness.source
Food Standards Agency (FSA) / Food Standards Scotland (FSS) (United Kingdom)	Approved	FSA and FSS concluded sufficient evidence of safety for biotin as a nutritional feed additive for all animal species, consistent with the 2025 EFSA FEEDAP Panel opinion; no new evidence of safety concern was identified. Approved under Assimilated Regulation (EC) No 1831/2003 with at least 97% purity (D-(+)-biotin).source
FSSAI (Food Safety and Standards Authority of India) (India)	Approved	Biotin is permitted as a micronutrient (vitamin) in health supplements and nutraceuticals under the FSS (Health Supplements, Nutraceuticals, Foods for Special Dietary Uses, Foods for Special Medical Purposes, Functional Foods and Novel Food) Regulations, 2016. Biotin-containing food products have received product approvals under FSSAI's non-specified food and food ingredient regulations.source

Who should approach with care

Whose guidance would steer them away.

Thyroid Disease — High-dose biotin supplementation interferes with thyroid immunoassays and can produce a false picture of Graves' disease or thyrotoxicosis, leading to misdiagnosis and unnecessary treatment in patients being monitored for thyroid conditions.

Heart Disease — FDA has documented a patient death following a falsely low troponin result caused by high biotin intake, meaning patients with cardiac conditions or those undergoing cardiac monitoring should disclose and limit high-dose biotin supplementation.

Diabetes — Excess biotin has a documented role in postprandial glucose control, and overdose signs can mimic hyperglycemia; diabetic patients should therefore exercise caution with high-dose biotin supplementation.

Epilepsy — Long-term anticonvulsant therapy (carbamazepine, phenytoin, phenobarbital, primidone) significantly lowers serum biotin levels by increasing catabolism and inhibiting intestinal absorption, so patients with epilepsy may need biotin status monitoring.

Research citations

The sources behind this verdict.

1FDA. Biotin – Health Professional Fact Sheet (NIH Office of Dietary Supplements). ods.od.nih.gov
2PubMed. Biotin: a scoping review for Nordic Nutrition Recommendations 2023, 2024. pmc.ncbi.nlm.nih.gov
3PubMed. Biotin – StatPearls, 2023. ncbi.nlm.nih.gov
4PubMed. Clinically Significant Lab Errors due to Vitamin B7 (Biotin) Supplementation: A Case Report Following a Recent FDA Warning, 2019. pmc.ncbi.nlm.nih.gov
5PubMed. Biotin interference: Underrecognized patient safety risk in laboratory testing, 2018. pmc.ncbi.nlm.nih.gov
6EFSA. Scientific Opinion on Dietary Reference Values for biotin, 2014. efsa.europa.eu

Independently researched6 citations