Although pirates were not the only victims. And while it may be fun to say, SCURVY, SCURVY, SCURVY, it certainly was not fun to have. So what is scurvy? Scurvy is simply a disease caused by a deficiency of vitamin C in the human body. Now in nature, in most cases, we humans have the advantage. You know, like the whole opposable thumb thing, you know. But there's one evolutionary advantage we missed out on that most animals have.