In the show, whenever an alchemist commits the taboo, they only lose one part of their body. Izumi lost organs, Ed lost his leg, and Mustang lost his eyesight. But, when Alphonse tried to transmute the soul he lost his entire body. Even though the equivalent exchange was justified for the other alchemists, I can't help but feel like Al's was not equivalent.
Can someone explain to me why he lost his whole body rather than just one part?