What is biotin?

Biotin is a water soluble B vitamin, also known as vitamin B7.

It is sometimes called vitamin H, from the German words Haar und Haut, meaning “hair and skin”. This reflects its importance for maintaining healthy hair and skin.

Biotin was identified as an essential nutrient during research into hair loss and skin changes. These effects were linked to consuming large amounts of raw egg whites.

Raw egg whites contain avidin, a protein that binds biotin and reduces its absorption. Biotin acts as a cofactor for enzymes involved in several important metabolic processes.

These include fatty acid synthesis, glucose production and amino acid metabolism.

Hair, skin, and nail health

Biotin is well known for supporting healthy hair, skin and nails. It is involved in keratin production, the structural protein found in hair and nails.

Biotin deficiency is uncommon with a varied diet. However, low biotin levels can contribute to thinning hair, brittle nails and skin changes.

Correcting a deficiency can help restore healthy hair, nails and skin. If you already get enough biotin, evidence for additional supplementation is less consistent.

However, many people report subjective improvements in hair thickness and nail strength with regular high dose biotin supplements.

Biotin also supports the maintenance of healthy skin and its natural barrier. This helps your skin retain moisture and stay resilient against environmental stressors.

Energy metabolism and blood sugar balance

Biotin’s role extends beyond hair, skin and nails. It acts as a cofactor for enzymes involved in energy metabolism and blood glucose regulation.

One of these enzymes is pyruvate carboxylase, which plays an important role in glucose production. Biotin also supports the metabolism of fats and amino acids.

These processes help your body convert food into cellular energy. Biotin also supports normal nervous system function and the maintenance of myelin around your nerve fibres.

This makes biotin important for maintaining healthy neurological function over time.

Supplementing with biotin

Biotin supplements range from modest doses in B complex formulas to standalone products containing 5,000 to 10,000mcg.

High dose supplements are commonly marketed for hair and nail support. Biotin is generally well tolerated, even at higher doses.

However, high dose biotin can interfere with some blood tests. These include thyroid function tests and certain cardiac biomarker tests.

If you take high dose biotin and need blood tests, tell your healthcare provider. They may advise you to stop taking it for a few days beforehand.