Actually, Iodide is a reduced form of iodine. When one adds electrons to a species, the process is reductive , its covered in most decent general chem texts
Oxidative states of Iodine include those in which a formal charge of +1, +3, +5, +7 can be attributed to an Iodine atom present in a complex anion such as hypoiodite, iodite, iodate, and periodate, respectively.