Katharine Bishop

Discovery of Vitamin E

After graduating from medical school, Bishop moved to Berkeley to teach histology in the anatomy department at the University of California Medical School until 1923. During this time, Bishop did her medical research with anatomist and endocrinologist Herbert McLean Evans. Together, they published a monograph on the vital staining of connective tissue cells. The discovery of Vitamin E came as a result of the study of the reproductive cycle of rats. After establishing a standard diet for the rats to maintain their regular reproductive cycle, Bishop and Evans started experimenting with dietary deficiencies. In 1923, they found a previously unknown factor that is vital for reproduction. When the rats were fed with a diet where lard was the only source of fat, though they grew healthily, the female rats were unable to carry babies full term due to the breakdown of the placentas, and the male rats became sterile since the sperm-forming cells in the testes would deteriorate. Initially called "Factor X", Bishop and Evans narrowed down that this factor came from the lipid extract of lettuce and wheat germ. The name "Vitamin E" later came after Vitamin D.

Later life

From 1924 to 1929, Bishop worked as a histopathologist at the George Williams Hooper Foundation for Medical Research in San Francisco. After her marriage and birth of her two daughters, she spent two years studying public health at the University of California Medical School. In mid-1930s, Bishop became a practicing physician and anesthesiologist at St. Luke's Hospital in San Francisco. She accepted a position at Alta Bates Hospital in Berkeley, California in 1940, and worked there until her retirement in 1953. She died at home in Berkeley in 1975.