If i take hair, skin, and nails vitamins.. how long will my hair grow by 3 months?

My hair was 3 inches past my shoulder and i cut it all the way up to my chin, then shorter again. i want to grow my hair back as fast as possible and i need to find out how long it might take for my hair to grow 3 months when taking vitaminsIf i take hair, skin, and nails vitamins.. how long will my hair grow by 3 months?
Get Ultra Nourishair by GNC it's specially for hair it has more vitamins and stuff to make your hair grow faster also use Mane n tail shampoo + conditioner and do a hot oil treatment called ';Doo grow'; (You can find it at your drug store) do the hot oil once a week and your hair should be a little past your chin in just afew weeks!