Vitamin C – the antiscorbutic
Dr Sean Bulley, a senior scientist with Plant & Food Research, outlines some of the history surrounding the discovery of vitamin C and explains why its chemical name is ascorbic acid. He outlines its main function in the body. He explains why humans, unlike most other mammals, have lost the ability to synthesise their own vitamin C.
Point of interest What is the recommended daily dose of vitamin C? Which fruits and vegetables are rich sources of vitamin C?
Transcript
DR SEAN BULLEY It was around 1910 the term ‘vitamin’ was coined by a researcher called Casimir Funk, and he introduced this concept to describe the micronutrients that are vital for your health that are non-minerals – so non-mineral micronutrients – and vitamin C was one of those.
It was known to be antiscorbutic – what that means its property that protects against a disease called scurvy. Scurvy is a nasty disease that results from the breakdown of collagen. Collagen is a very vital constituent of all your connective tissues – it’s a structural protein – and it was only until about the 1930s that vitamin C was pinned down and identified as a 6-carbon acid, and it was named L-ascorbic acid, in reference to the antiscorbutic properties. So you have the two terms still lingering today – vitamin C and ascorbic acid.
Surprisingly, many animals can’t produce our own vitamin C, and these can include humans, bats, other mammals such as guinea pigs, even some freshwater fishes and birds. In mammals, what has happened is that the final step of the biosynthetic pathway – the enzyme that catalyses this reaction – is mutated and is non-functional. We are blocked at that last step.
In a normal varied diet, you get enough vitamin C to happily survive on, and so it hasn’t been a great selective pressure on the populations.
Acknowledgements: LIFE.com Painting, 'James Lind: Conqueror of Scurvy', by Robert Thom. Collection of the University of Michigan Health System, Gift of Pfizer Inc. UMHS.17 CDC Vincent Ho Pieter Prinsloo John Ombiga The New Zealand Medical Journal. New Zealand Medical Association (NZMA) Health Plus UK Ltd Packa 123rf Sandeep Gangadharan Vitamin C booster reprinted by permission from Macmillan Publishers Ltd: Nature Biotechnology, 2003.
