Vitamin B7 (Biotin)

Physiological Functions

1. Core Role in Energy Metabolism

    

   Biotin acts as a coenzyme for five key carboxylase enzymes that participate in the breakdown and synthesis of macronutrients:
    
   • Converts carbohydrates into glucose for energy production.
   • Facilitates the metabolism of fats and amino acids.
   • Supports gluconeogenesis—the process of making glucose from non-carbohydrate sources (e.g., amino acids, glycerol) during periods of fasting.
    
2. Maintenance of Hair, Skin, and Nail Health

    

   Biotin is widely recognized for its role in promoting the growth and integrity of hair, skin, and nails. It supports the production of keratin—a structural protein that forms the basis of these tissues. Deficiency often manifests as brittle nails, hair loss, and a scaly, red rash around the eyes, nose, and mouth (known as seborrheic dermatitis).
    
3. Nervous System and Cognitive Function

    

   Biotin contributes to the synthesis of fatty acids and neurotransmitters that are essential for normal brain function and nerve signal transmission. Adequate intake helps maintain cognitive health and may reduce the risk of neurological symptoms associated with deficiency.
    
4. Blood Sugar Regulation

    

   Emerging research suggests that biotin may help regulate blood glucose levels by enhancing the activity of insulin and improving glucose uptake in cells. This makes it potentially beneficial for individuals with type 2 diabetes, though more clinical studies are needed to confirm its efficacy.
    

Deficiency and Toxicity

• Deficiency Symptoms
   
  Biotin deficiency is rare in healthy individuals with a balanced diet. At-risk groups include people who consume large amounts of raw egg whites, individuals with malabsorption disorders (e.g., celiac disease, Crohn’s disease), and pregnant women (biotin requirements increase during pregnancy). Symptoms include hair loss, brittle nails, skin rashes, fatigue, depression, and neurological issues like numbness or tingling in the extremities.
• Toxicity
   
  Biotin has an extremely low toxicity profile. As a water-soluble vitamin, excess amounts are excreted in urine rather than stored in the body. No serious adverse effects have been reported with oral supplementation, even at doses far exceeding the recommended intake. High doses may, however, interfere with certain laboratory tests (e.g., thyroid hormone tests), leading to false results.