Answer
The Nobel Prize in Physiology or Medicine was awarded in 1929 to Frederick Gowland Hopkins and Christiaan Eijkman for their discovery of vitamins. Hopkins discovered that the growth of rats was dependent on an unknown dietary factor, which he named "vitamin A". Eijkman discovered that beriberi was caused by a deficiency of vitamin B1. These discoveries led to the development of vitamin supplements and the prevention of vitamin deficiency diseases.