The Great Pellagra Epidemic of 1915

You're thinking, "What? Pellagra Epidemic?" Yea, I did too, but apparently, this epidemic is what lead to the discovery and identification of pellagra as a disease caused by vitamin deficiency, specifically Vitamin B3. Pellagra was found to be a vitamin deficiency by Dr. Joseph Goldberger:

The puzzle of pellagra was solved by Dr. Joseph Goldberger. Dr. Goldberger was assigned in 1914 by the US Public Health Service to the South to deal with pellagra. After inspecting Southern orphanages, mental hospitals and prisons, Goldberger made the pivotal observation that the malnourished inmates of those institutions often developed pellagra while the better-fed staff did not. Pellagra, he deduced, did not arise from germs, as was commonly believed, but rather from a nutritional deficiency. To prove this, Dr. Goldberger, his assistants and even his wife engaged in experiments called "filth parties." They injected themselves with blood or ingested the scabs, feces and body fluids of patients. None developed pellagra. He also did decisive experiments with Mississippi prison inmates (who "volunteered" in return for a full pardon). Dr. Goldberger fed them a poor diet that he believed caused pellagra and within months, many developed the disease. He then added meat, fresh vegetables and milk to their diet and reversed all of the signs and symptoms of pellagra. Dr. Goldberger never identified the dietary principle that had this extraordinary effect. He died in 1929 (of kidney cancer). Eight years later, the factor was found to be niacin. This discovery was made in 1937 at the University of Wisconsin. Niacin is abundant in red meat, fish, poultry, and green leafy vegetables. Niacin can prevent pellagra (and can cure it).

Another point of interest: the name "pellagra" comes from the Italian "pelle", skin + "agra", rough = rough skin, referring to the skin problems in pellagra.

Want to read more? Italians also were involved with atropine, as well as pretty women.