Vitamin B7 (Biotin)

What It Is

Biotin, also known as Vitamin B7 or sometimes Vitamin H (from the German words Haar und Haut, meaning “hair and skin”), is a water-soluble B-complex vitamin. It plays a vital role in numerous metabolic processes, particularly those involving the conversion of food into energy.

Biotin is naturally present in many foods such as:

• Eggs (especially yolks)
• Nuts and seeds
• Legumes
• Whole grains
• Organ meats (like liver)
• Certain vegetables like sweet potatoes and spinach

It is also produced in small amounts by the gut microbiota.

How It Works

Biotin functions as a coenzyme in carboxylation reactions — essential chemical processes in which carbon dioxide is added to other molecules. These reactions are critical in:

Macronutrient metabolism:

• Carbohydrates: Helps convert glucose into energy.
• Fats: Assists in synthesizing fatty acids and breaking down fatty acids for energy.
• Proteins: Supports amino acid metabolism and gluconeogenesis (production of glucose from non-carbohydrate sources).

Gene regulation and cell signaling:

• Biotin modifies certain proteins (via biotinylation), which can influence gene expression and cellular growth.

Keratin infrastructure:

• Biotin supports the formation of keratin, a key structural protein in hair, nails, and skin — hence its association with beauty and cosmetic health.

Why It’s Important

Biotin is essential for maintaining:

• Healthy hair, skin, and nails: Deficiency can cause brittle nails, hair loss (alopecia), and rashes.
• Energy metabolism: It’s necessary for converting dietary nutrients into usable cellular energy.
• Nervous system health: Supports nerve function and cognitive health.
• Fetal development: Adequate biotin is important during pregnancy for embryonic growth and development.

Although true biotin deficiency is rare in healthy individuals, it may occur due to:

• Prolonged consumption of raw egg whites (which contain avidin, a biotin-binding protein)
• Malabsorption disorders
• Long-term use of certain medications (like anticonvulsants or antibiotics)
• Genetic metabolic disorders (such as biotinidase deficiency)

Considerations

Deficiency Signs:

• Thinning hair or hair loss
• Scaly or red rash around eyes, mouth, or nose
• Fatigue and muscle weakness
• Neurological symptoms such as depression or tingling in extremities

Supplementation:

• Recommended dietary intake: about 30 micrograms/day for adults, and 35 micrograms/day for lactating women.
• Common supplements (especially in “hair, skin, and nails” formulas) often contain 5,000–10,000 micrograms (5–10 mg) — much higher than the daily requirement, but generally considered safe because biotin is water-soluble and excess amounts are excreted in urine.

Interactions and Precautions:

• Lab test interference: High doses of biotin can interfere with certain lab assays, leading to false readings — especially for thyroid, troponin (heart attack), and hormone tests.
• Pregnancy and lactation: Generally safe at recommended doses but consult a healthcare provider before supplementing.
• Medical conditions: Individuals with kidney disease, diabetes, or those on long-term medication should use biotin supplements cautiously.