This term describes a suite of chemicals found to be critical in metabolizing fat and carbohydrates, as well as performing a number of other functions in the human body. These chemicals are grouped thus because they were originally discovered together in such foods as yeast and liver. Chemicals in this group, when present in vegetables, fruits, and grains, are unstable at high temperatures, and nutritional benefits may decrease when those foods are cooked thoroughly. The traditional members of the vitamin B complex group are: