Which vitamin deficiency can lead to brittle nails?

• A. Vitamin B7 (Biotin)
• B. Vitamin D
• C. Vitamin C
• D. Vitamin E

Answer: (A)

Brittle nails are often associated with a deficiency in vitamin B7, also known as biotin. Biotin plays a critical role in the health of nails, hair, and skin, as it is involved in the synthesis of keratin, which is the primary protein that makes up nails. When there is an insufficient amount of biotin, it can lead to weak and brittle nails that are prone to breaking and splitting.

While the other vitamins listed—D, C, and E—have their own important roles in overall health and wellbeing, they do not specifically address the structural integrity of nails in the same way that biotin does. For instance, while vitamin D is vital for bone health and can impact skin health, it does not directly influence nail strength. Vitamin C is crucial for collagen production and immune function, and vitamin E is an antioxidant that supports skin and nail health, but neither is as specifically linked to the strength and resilience of nails as biotin is. Thus, biotin deficiency is directly related to the condition of brittle nails, making it the correct answer.