Vitamin B7 (biotin) is essential for converting carbohydrates, fats, and proteins into usable energy as a coenzyme for carboxylase enzymes. It supports healthy hair, skin, and nails, aids nervous system function and gene expression, and contributes to normal fetal development during pregnancy. Biotin also helps maintain stable blood sugar and overall metabolic health.

Vitamin B7 (biotin) is found in foods such as egg yolks, liver, salmon, dairy, nuts (especially almonds and peanuts), seeds, soybeans and other legumes, whole grains, mushrooms, cauliflower, bananas and avocados. Note raw egg whites contain avidin, which binds biotin—cooking reduces avidin and makes biotin more available. A balanced diet usually supplies adequate biotin; supplements are rarely necessary unless prescribed.

Biotin (vitamin B7) deficiency is uncommon but causes hair thinning or loss, brittle nails, scaly red dermatitis around the eyes, nose and mouth, conjunctivitis, fatigue, depression, paresthesia and neurological signs (e.g., lethargy, hallucinations). Infants may develop hypotonia and seizures. Risk factors include prolonged raw egg‑white intake, total parenteral nutrition without supplementation, biotinidase deficiency, long‑term antibiotics or certain anticonvulsants.

Biotin is vitamin B7 (also called vitamin H), not B12. It’s a water‑soluble B‑vitamin essential for metabolism of fats, carbohydrates and amino acids and for healthy hair, skin and nails. Vitamin B12 (cobalamin) is a separate B‑vitamin needed for red blood cell formation and nerve function. Both are distinct nutrients with different roles and deficiency signs.

Biotin deficiency can cause hair thinning or patchy hair loss, brittle nails, dry scaly or rash-prone skin (especially around the face), conjunctivitis, and mouth soreness. Neurological signs include tingling or numbness in hands and feet, muscle pain, fatigue, depression, and in severe cases confusion or seizures (especially in infants). Appetite loss and developmental delay may occur in babies.

Biotin (vitamin B7) can improve hair quality and growth in people with a confirmed deficiency, but there’s little reliable evidence that it boosts hair growth in those with normal biotin levels. Routine high‑dose supplementation is not proven effective and may interfere with lab tests. If you have hair loss, check with a healthcare provider to evaluate causes and possible nutrient deficiency before starting biotin.