Who invented the vitamin?

Frederick Gowland Hopkins
Sir Frederick Gowland Hopkins OM, PRS (20 June 1861 – 16 May 1947) was an English biochemist who was awarded the Nobel Prize in Physiology or Medicine in 1929, with Christiaan Eijkman, for the discovery of vitamins, even though Casimir Funk, a Polish biochemist, is widely credited with discovering vitamins. He also discovered the amino acid tryptophan, in 1901. He was President of the Royal Society from 1930 to 1935.