Which vitamin is also known as thiamine and is part of a coenzyme needed for energy metabolism?

Thiamine, also known as Vitamin B1, plays a crucial role in energy metabolism within the body. It is a vital component of coenzymes that are necessary for the proper functioning of cellular processes, particularly in converting carbohydrates into energy. Thiamine supports the enzyme functions that help to produce ATP (adenosine triphosphate), which is the main energy currency of cells. This makes it essential for cellular energy production, particularly in tissues that have high energy demands such as the heart and brain.

In contrast, the other B vitamins listed have different roles in metabolism and energy production. Vitamin B2, known as riboflavin, is primarily involved in the metabolism of fats, carbohydrates, and proteins, while Vitamin B3 (niacin) is important for DNA repair and the production of certain hormones. Vitamin B5, or pantothenic acid, is vital for synthesizing coenzyme A, which is important in fatty acid metabolism. Thus, Vitamin B1 (thiamine) is uniquely positioned as the specific vitamin that fits the description provided in the question regarding its role in energy metabolism as a coenzyme.