Inositol is also referred to as vitamin B8, although it is not technically a vitamin, rather it is a type of sugar that has several important functions. Inositol in the human body was discovered more than 150 years ago. The first isomer (rearranged chemical structure) of it, "myo-inositol", was isolated in 1850, and fully “purified” in 1887. It plays a structural role in the body as part of the cell membranes and it forms a component of every cell membrane in the body. Inositol is most commonly found in citrus fruits, green leafy vegetables, seeds, wholegrains and nuts.