Evolution of Vitamin C

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Some 400-300 million years ago (Mya) when living plants and animals first began the move from the sea to rivers and land, environmental iodine deficiency was a challenge to the evolution of terrestrial life (Venturi et al., 1999; 2000). In plants, animals (and fishes) the terrestrial diet became deficient in many essential marine micronutrients, including iodine, selenium, zinc, copper, manganese, iron, etc.. Freshwater algae and terrestrial plants, in replacement of marine antioxidants, slowly optimized the production of other endogenous antioxidants such as ascorbic acid, polyfenols, carotenoids, flavonoids, tocoferols etc., some of which became essential “vitamins” in the diet of terrestrial animals (vitamins C, A, E, etc.).

Ascorbic acid (“Vitamin C” for humans) is a common enzymatic cofactor in mammals used in the synthesis of collagen. Ascorbate is a powerful reducing agent capable of rapidly scavenging a number of ROS. Freshwater teleost fishes also require dietary vitamin C in their diet or they will get scurvy (Hardie et al.,1991). The most widely recognized symptoms of vitamin C deficiency in fishes are scoliosis, lordosis and dark skin coloration. Terrestrial freshwaters salmonids also show impaired collagen formation, internal/fin haemorrhage, spinal curvature and increased mortality. If these fishes are housed in seawater with algae and phytoplankton, then vitamin supplementation seems to be less important, presumably because of the availability of other, more ancient, antioxidants in natural marine environment (Hardie et al.,1991).

Venturi and Venturi (2004, 2007) suggested that the antioxidant action of ascorbic acid developed firstly in plant kingdom when, about 500 Mya, plants began to adapting themselves to mineral deficient fresh-waters of estuary of rivers. Some biologists suggested that many vertebrates had developed their metabolic adaptive strategies in estuary environment (Purves et al., 1998). Like plants, most mammals (with the exception of humans and guinea pigs) make their ascorbic acid from glucose and can make glucose from ascorbic acid. Some primates, remote ancestors of humans, underwent a genetic mutation about 40-45 million years ago and haven't been able to make “vitamin C” since. Therefore living humans need nowadays to get all “vitamin C” from food. Some scientists think that the loss of human ability to make “vitamin C” may have caused Homo sapiens' rapid evolution into modern man (Challen et al., 1998; Benhegyi et al., 1997; Stone, 1979).

[edit] References

1. Benhegyi, G. 1997. Ascorbate metabolism and its regulation in animals. Free Radical Biology and Medicine. 23(5):793-803.

2. Challen, JJ, Taylor, EW. 1998. Retroviruses, ascorbate, and mutations, in the evolution of Homo sapiens. Free Radical Biology and Medicine. 25(1):130-132.

3. Hardie LJ, Fletcher TC, Secombes C.J.1991. The effect of dietary vitamin C on the immune response of the Atlantic salmon (Salmo salar). Aquaculture 95:201–214

4. Purves WK, Sadava D, Orians GH, Heller HC. 1998. Life.The Science of Biology. Part 4: The Evolution of Diversity. Chapter 30

5. Stone I. 1979. Homo sapiens ascorbicus, a biochemically corrected robust human mutant. Medical Hypotheses. 5(6):711-721

6. Venturi S, Venturi M. 1999. Iodide, thyroid and stomach carcinogenesis: Evolutionary story of a primitive antioxidant? Eur J Endocrinol . 140:371-372.

7. Venturi S, Donati FM, Venturi A, Venturi M. 2000. Environmental iodine deficiency: A challenge to the evolution of terrestrial life? Thyroid. 10 (8):727-9.

8. Venturi S. and Venturi M. 2004. Iodine and Evolution. Dimi Marche News. Dipartimento Interaziendale di Medicina Interna della Regione Marche. Published on-line, February 8, 2004. http://web.tiscali.it/iodio/

9. Venturi S, Venturi M. Evolution of Dietary Antioxidant Defences. European EPI-Marker. 2007, 11, 3 :1-12

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