Another name for vitamin b1

There are several B vitamins. B1 is thiamine, B2 is riboflavin, B3 is niacin, B5 is pantothenic acid, B6 is pyridoxine, B7 is biotin, B9 is folic acid, and B12 is cyanocobalamin. In some of these cases it's possible for more than one compound to work equally well as a vitamin: for example, nicotinamide instead of niacin. The reason some numbers are "skipped" is that they were given to compounds that later turned out not to be necessary in the human diet (in most cases, because the human body is capable of synthesizing them from simpler components).