People supplement with Inositol to support healthy brain and nervous system function. ** Vitamin World’s Inositol Powder is a vitamin-like substance that is very closely-related to the family of B Vitamins, also referred to as Vitamin B8. Playing an important part in the growth and functioning of healthy cells, people have traditionally taken inositol to help with several different cognitive functions. Inositol is an important part of phospholipids in cell membranes that contribute to healthy cell growth and function.