Corn was not accepted as food for humans in all of Europe, field or dent corn was animal fodder first. To many Scandinavians and Germans this remained true into the 20th cent. because many did not realize sweet corn was different from field corn. This may have saved them from pellagra.
Corn spread through the 16th Cent. carried by the Portuguese traders into Asia.
In Italy corn meal became the staple, polenta. Corn reduced the incidence of famine causing death because it is higher yield cereal than wheat, barley or rye. Corn seemed to be a much more reliable crop. The impoverished southern European, peasantry, soon subsisted on high carbohydrate/low protein corn that lacks bioavailable (absorbable) B3 (niacin) unless properly treated with lime.
1735 Spain – Don Gaspar Casal wrote the first description of pellagra among Spain's Asturia region peasants who ate mostly maize. Casal thought it was a type of new leprosy or due to eating spoiled corn.
1771 Francesco Frapoli coined the name pellagra in his description of Italian peasants with the disease.
http://books.google.com/books?id=azXx4cbrMZMC&pg=PA33&lpg=PA33&dq=zea+mays+niacin++pellagra&source=bl&ots=hRspzQxrvH&sig=Nb7u4WPs_w4Reh_BHnr7tSJ8mRY&hl=en&sa=X&ei=cIpyU-HCI4_roATcgoKwAQ&ved=0CFYQ6AEwBQ#v=onepage&q=zea%20mays%20niacin%20%20pellagra&f=false
They suffered from pellagra that caused sensitivity to sunlight, skin lesions, diarrhea, mental deterioration and eventual death.
American medical journals of 1909 reported Italy had 104,067 cases of pellagra in 1881 and still had 50,000 cases in 1908. This dietary deficiency persisted in Europe until the 1950s, even though Goldberger worked out the etiology of pellagra around 1915.
http://books.google.com/books?id=M7EDAAAAYAAJ&pg=PA175&lpg=PA175&dq=Italy+have+104,067+cases+of+pellagra+in+1881&source=bl&ots=z0PCztEolA&sig=G6KQ64rw6rVUVypsu9ysZSF4SBs&hl=en&sa=X&ei=95FyU4GkL4aBogSekoLYBg&ved=0CDMQ6AEwAQ#v=onepage&q=Italy%20have%20104%2C067%20cases%20of%20pellagra%20in%201881&f=false
History of pellagra in Italy due to maize replacing previous cereals in diet.
http://www.isita-org.com/jass/Contents/2007%20vol85/Articoli/JassPDFAggiunte/Mariani2007.pdf
Some think the vampire legends resulted from the introduction of corn and the new dietary deficiency creating a reaction to sunlight.
Pellagra and the origin of a myth: evidence from European literature and folklore.
http://jrs.sagepub.com/content/90/11/636.extract
Origin of the myth of vampirism.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1296514/
Origin, History, and Uses of Corn (Zea mays)
http://agron-www.agron.iastate.edu/Courses/agron212/readings/corn_history.htm
Discussion of Asian records of corn in cooking
http://chowhound.chow.com/topics/717966
Check out the book 'Why We Eat What We Eat: How the Encounter between the New World and the Old Changed the Way Everyone on the Planet Eats by Sokolov