Which of the following is not a macromolecule important for body functions?

Vitamins are classified as micronutrients, which means they are required by the body in smaller amounts compared to macromolecules. While vitamins play essential roles in various biochemical functions, including serving as coenzymes and antioxidants, they do not fall under the category of macromolecules such as carbohydrates, nucleic acids, and proteins.

Macromolecules like carbohydrates provide energy, nucleic acids are crucial for genetic information and protein synthesis, and proteins perform a wide range of structural and functional roles within the body, including acting as enzymes, hormones, and antibodies. Thus, the unique classifications of vitamins as micronutrients distinguish them from the key macromolecules that contribute significantly to body functions in larger quantities.