How Scientists Discovered That The Mysterious 'Extrinsic Factor' in Liver was Vitamin B12
In 1926, Harvard physicians discovered that eating half a pound of liver daily would prevent Pernicious Anemia. The hunt was on to identify the compound in liver that was responsible. In 1947, Karl Folkers (a scientist at Merck) isolated the tiny red crystals of vitamin B12. 'Extrinsic Factor' now had a name.