Final answer:
The statement is false. B vitamins are critical for protein and carbohydrate metabolism and also play a significant role in fat metabolism, including fat synthesis and breakdown.
Step-by-step explanation:
The statement that B vitamins play a critical role in protein and carbohydrate metabolism but are only minimally important in fat metabolism is false. B vitamins are essential nutrients that function as coenzymes and cofactors in various biochemical reactions, including those involved in energy and amino acid metabolism, as well as fat synthesis and breakdown. In particular, Vitamin B₅ (pantothenic acid) is crucial for the synthesis of coenzyme A, which plays a pivotal role in the metabolism of carbohydrates, proteins, and fats. Therefore, they are not only important in protein and carb metabolism but also significantly involved in fat metabolism.