Which macronutrient is important for the structure of skin, hair, and nails?

Proteins play a crucial role in the structure of skin, hair, and nails due to their composition of amino acids, which are the building blocks of these tissues. For instance, keratin is a type of protein that is a key structural component in hair and nails, providing strength and resilience. Similarly, collagen, another protein, is essential for the integrity and elasticity of skin, helping it maintain its structure and firmness.

While carbohydrates, lipids, and minerals have their own important functions in the body—such as providing energy, contributing to cell structure, and supporting various physiological processes—the primary structural components of skin, hair, and nails are indeed proteins. Therefore, the significance of proteins in maintaining and building these tissues underscores why they are identified as the correct answer in this context.