Supplement of essential Vitamin B1 (Thiamine). Thiamine (Vitamin B1) plays an important role in the metabolism of carbohydrates, and energy production for all cells. Thiamine is most important in the breakdown of pyruvic acid, a waste product in hard working muscles, along with lactic acid. In any situation where carbohydrates are the major energy source, or when glucose is added to the diet, thiamine requirement is increased significantly.