Scurvy is another interesting and severe disease, and because of what it tells us: how little we know about the disease. In theoretical terms, scurvy is caused by the lack of Vitamin C, but the three primary medical texts: Lange's, Merck's, and Harrison's, do not document a cure - they recommend a treatment, which is a treatment that does not, in actual practice, cure. The recommended treatment is Vitamin C that only addresses symptoms, not causes.