Ever since it became clear that vitamins in food play an essential role in maintaining health and preventing diseases, these nutrients found themselves the subject of intense scrutiny by scientists eager to identify the active components and their chemical make-up. The 1937 Nobel Prize in Chemistry rewarded Walter Haworth and Paul Karrer for their individual breakthroughs that provided the first structural lessons in understanding Nature’s alphabet of vitamins.

After Walter Haworth’s pioneering demonstration that the carbon atoms that make up sugar molecules exist in a ring-like, rather than a straight-line, arrangement, he then turned his attention to the composition of vitamin C. Thanks to the knowledge that the chemical elements that make up vitamin C resemble that of simple sugar molecules, and to Albert von Szent-Györgyi, the 1937 Medicine Laureate, making his pure extracts of vitamin C freely available, Haworth deduced the correct chemical structure of the vitamin. From this, Haworth and his colleague Edmund Hirst successfully synthesised vitamin C in the laboratory, making this the first vitamin to be artificially produced. Their breakthrough made it possible for vitamin C, or ascorbic acid as Haworth called it, to be produced cheaply on a large scale for medicinal use.

Paul Karrer’s entry into the field of vitamins came through his research on the chemistry of carotenoids, a family of orange-yellow plant pigments that are related to the pigment in carrots. Karrer worked out the chemical structures of several carotenoids, and he showed that one of these, carotene, is converted into vitamin A in the body. His original formula for carotene was eventually refined by Richard Kuhn, making the first time that the structure of a vitamin or its precursor had been established. Karrer also determined that the structure of active vitamin A is half of its precursor molecule. Karrer also helped to illuminate our knowledge of another vitamin by deriving the chemical structure of factoflavin. A natural yellow-coloured substance that glows green, factoflavin is part of the complex originally described as vitamin B2.