Which nutrients function as coenzymes and are needed in only small amounts?

Vitamins

Explanation:

The organic molecules which are needed by the organisms in small amounts in order to maintain the proper functioning of the metabolic processes of organisms are known as vitamins.

There are various biochemical functions that the vitamins perform in the body of organisms. As for example some functions have been mentioned below -

Vitamin A regulated cell growth and tissue differentiation. Vitamin D regulates the mineral metabolism for the bones. Vitamin B complex functions as a coenzyme. Vitamin C and E both function as the antioxidants in the body of organisms.