What is the role of biotin in metabolism?

Biotin plays a crucial role in metabolism primarily by acting as a coenzyme for several carboxylation reactions. It is essential for converting food into energy, as it aids in the metabolism of macronutrients, including carbohydrates, fats, and proteins. Biotin facilitates the conversion of pyruvate to oxaloacetate, a critical step in gluconeogenesis, and is involved in fatty acid synthesis and amino acid metabolism. This role makes biotin an integral part of processes that help maintain energy levels and support various bodily functions related to metabolism.

Other options do not accurately represent the primary function of biotin. For example, while maintaining blood sugar levels is vital for overall health, this is not a direct role of biotin itself. Similarly, biotin does not promote digestive health or enhance calcium absorption; these functions are associated with different nutrients and mechanisms within the body. Thus, the correct answer emphasizes biotin's fundamental importance in macronutrient metabolism.