Vitamin B1 was the first component of the vitamin B complex to be discovered, and is commonly known as thiamine. It is necessary in reactions to free energy from carbohydrates and their transformation into the simple sugar, glucose. It is also important for the healthy functioning of the nervous system, considering that it enables the healthy development of the myelin sheath that surrounds most nerves. Oranges, baker's yeast, beans and whole grains are good sources of vitamin B1.