Heilmann E, Bender F
Thoraxchir Vask Chir. 1977 Jun;25(3):152-4. doi: 10.1055/s-0028-1096705.
The pathogenesis of anemia in 84 patients with valvular protheses of the heart was investigated. A secondary deficiency of serum iron and folate, caused by chronic hemolysis, was found. There was no indication of vitamin-B12-deficiency.