There is a lot of discussion about the B complex vitamin and how it is essential for the body to perform a wide range of functions. However, the B complex vitamin just isn’t simply one very complex vitamin, as the title may suggest. There are really eight B vitamins that are within the B complex vitamin in addition to a few other associated substances. The eight vitamins that make up the B complex vitamin are thiamine or vitamin B1, riboflavin or vitamin B2, niacin or vitamin B3, pyridoxine or vitamin B6, cobalamine or vitamin B12, folic acid, pantothenic acid and biotin. The other related substances that are also in the B complex vitamin include choline, inositol and para-aminobenzoic acid.