What substance are nails primarily composed of?

Nails are primarily composed of a protein called keratin. Keratin is a fibrous structural protein that is not only found in nails but also in hair and the outer layer of skin. It provides strength and resilience, which is essential for protecting the tips of fingers and toes. The characteristic hardness of nails is attributed to keratin, which can be found in various forms throughout the body, adapting to the needs of different tissues.

While collagen is an important structural protein in connective tissues, it does not constitute the main component of nails. Calcium is also essential for overall nail health and strength, but it is not a primary constituent of the nail structure itself. Chitin, a polymer found in the exoskeletons of arthropods, is unrelated to human nails. Understanding the composition of nails emphasizes the significance of keratin in both their formation and function.