Maize contains the vitamin niacin, but not in a form the body can absorb  Pellagra is a disease that results from niacin deficiency  When maize was introduced into southern Europe from the Americas in the eighteenth century, it quickly became a dietary staple, and many Europeans who came to subsist primarily on maize developed pellagra
Pellagra was virtually unknown at that time in the Americas, however, even among people who subsisted primarily on maize
In southern Europe many of the people who consumed maize also ate niacin-rich foods.