biotiinia

Biotin, also called vitamin B7 or vitamin H, is a water-soluble vitamin in the B-complex group. It functions as a coenzyme for carboxylase enzymes involved in the metabolism of fats, carbohydrates, and amino acids, including acetyl-CoA carboxylase, pyruvate carboxylase, and propionyl-CoA carboxylase. Through these reactions, biotin supports fatty acid synthesis, gluconeogenesis, and amino acid catabolism.

Biotin is widely distributed in foods. Good sources include egg yolk, organ meats, nuts, seeds, legumes, and some vegetables. The human gut also produces small amounts of biotin through microbial synthesis. In a varied diet, biotin intake is typically sufficient for most people.

Deficiency of biotin is uncommon in healthy individuals but can occur with prolonged consumption of raw egg whites (which contain avidin that binds biotin), malabsorption disorders, genetic conditions such as biotinidase deficiency, or long-term use of certain medications. Symptoms of deficiency can include thinning hair, brittle nails, dermatitis, glossitis, and, in severe cases, neurological issues.

Biotin supplements are used to treat deficiency and are widely marketed for hair and nail health. For people without deficiency, evidence of cosmetic benefit is limited. There is no established upper intake level for biotin; it is generally well tolerated, but very high doses can interfere with certain laboratory tests, potentially producing misleading results. Individuals should consult a clinician before taking high-dose supplements, especially when undergoing lab testing.

Biotin was identified in the early 20th century and later characterized as a coenzyme for multiple carboxylase reactions, underscoring its essential role in metabolism.