Anemia and intestinal dysfunction in former residents of the Caribbean.

A group of subjects had common features of megaloblastic anemia due to vitamin B12 deficiency, normal or high serum folate, and evidence of intestinal malabsorption. They were all former residents of the Caribbean area now living in New York City. Despite similar symptoms and diagnostic studies, two subjects were found to have pernicious anemia and three to have tropical sprue. Achlorhydria, serum anti-intrinsic factor antibody, the severity of small intestinal abnormalities, and posttherapy Schilling tests were helpful differential factors. These subjects illustrate the problems that may be encountered in differentiating tropical sprue and pernicious anemia.