Casimir Funk was a Polish-born American biochemist who pioneered research on dietary requirements and vitamins, especially vitamin B1 which is also known as thiamine. He is also recognized for his research into animal hormones, and the biochemical aspects of diabetes, cancer and ulcers.

Casimir was born in Warsaw on February 23, 1884, the son of a well-known dermatologist. He attended the University of Bern, Switzerland and in 1904 obtained his Ph.D. in organic chemistry at age 20. Prior to emigrating to the United States in 1915, he worked at the Pasteur Institute in Paris and the Lister Institute in London. In 1920, he became a naturalized American citizen. Funk returned to Warsaw in 1923 under the sponsorship of the Rockefeller Foundation to assume the role of Director of the Biochemistry Department of the State Institute of Hygiene. He left this position in 1927 due to political turmoil and went to Paris where he founded the...