“Experimental Human Scurvy”, John H. Crandon, Charles C. Lund, David B. Dill1940-09-05 (, )⁠:

[historical background] A normal active adult placed himself on a vitamin C-free diet supplemented by the other known vitamins for a period of 6 months. The findings in this state of pure vitamin C deficiency [scurvy], that is, in the absence of factors such as multiple avitaminoses, infection, growth or other stress, were as follows:

[A remarkable n = 1 self-experiment with extensive quantified data, which helps establish important things about disease like how lack of vitamin C intrinsically disables wound healing—results which ordinary scientific methods would struggle to establish with just animal experiments or correlational methods.]