This is so interesting! I've never heard of pellagra before, but this reminds me of a story a former German professor told my class. Interestingly he corroborated Fairchild's "pickiness" argument, saying that the Germans/Austrians equated corn to pig food. Your answer makes much more sense and is certainly richer. Thanks for sharing!
RE: Wartime Rationing, Food Aid, and "Civilized" Sickness: The Problem of Pellagra in 1918