Vitamin C is a simple organic molecule called ascorbic acid (also known as E300). Like other vitamins it is a chemical needed in tiny amount by the body in our diet. Other animals (like all carnivorous mammals) can manufacture it within their body. An enzyme produced in liver cells can convert simple sugars into ascorbic acid acid. The gene to make this enzyme is present in the human genome but in an inactive form (known as a pseudogene). The same pseudogene is present in the DNA of other primates, which is one of the ways in which human ancestry can be traced back through our evolutionary ancestors.
According to the NHS website, good sources of vitamin C include oranges, red and green peppers, strawberries, blackcurrants, potatoes, broccoli & brussel sprouts. The recommended daily allowance (RDA) of vitamin C varies from country to country with the UK recommending 40 mg per day and Japan suggesting 100 mg per day. It is probably irrelevant though because if you eat a balanced diet you are almost certainly consuming about 150 mg of the vitamin every day. It is possible to take too much vitamin C. If you consumer over 1000 mg per day you run the risk of stomach pain, diarrhoea & flatulence so be wary of eating too many of those tasty vitamin supplements!.
Vitamin C is involved in several biological processes, the two most significant of which are making collagen and as an antioxidant. One of the problems of relying on oxygen for our energy production is that oxygen can be very poisonous – I know, crazy isn’t it! If single oxygen atoms (known as free radicals) form inside the body they can start a series of reactions that damage cells. Free radicals also help by killing bacteria so don’t be taken in by so-called super foods that claim to be a “great source of antioxidants“. The evidence suggests that antioxidants and free radicals should exist in a balance within a healthy human body.
Vitamin C’s most important role is probably in producing collagen (the most abundant protein in humans) which is the connective tissue between bones and gives skin its elasticity. Ascorbic acid helps wounds to heal because this process relies upon the production of collagen. It is the lack of collagen that produces the most obvious symptoms of scurvy – bleeding gums and open sores.
In the 1970s, double Nobel Prize winner Linus Pauling pushed the idea that vitamin C was helpful in the treatment of colds. I think that most people of my generation will have been told to “take lots of vitamin C” when we have a cold. It may not be something that you have heard. I hope not because the research over the last 40 years suggests that vitamin C has little to no effect upon the common cold. Just because Linus Pauling was brilliant in one field of science does not make him an authority in other areas! There are no authorities in science; just a community of individuals working towards a greater understanding of nature.
Questions…
- If some ascorbic acid was burnt in a good air supply, what two products would you expect to be produced?
- What is an enzyme?
- Suggest a “simple sugar”.
- Genes are the codes to build proteins. From what type of molecules are proteins built?
- As well as vitamin C, what other major dietary nutrient is provided by brussel sprouts?
- What is the name of the energy producing reaction involving oxygen within living cells?
- What feature distinguishes single-celled protista from single-celled bacteria?
- Which mineral combines with collagen to form bones?
- What kind of organism causes the common cold?
- For what did Linus Pauling win his two Nobel Prizes? What makes this achievement unique?
Like, seriously, most questions evs, OK?
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