Vitamins

There has, in recent years, been some debate about the need to take vitamin tablets. Vitamin is a compound word derived from ‘vital amines’. The vitamins are a range of essential chemicals needed by our body. They were given letters of the alphabet in the order they were discovered and the letters bear no relationship to their structures or order of importance. It was originally thought that there was only one ‘B’ vitamin, but when it was eventually analysed it was realized that it was a complex mixture of a number of compounds, hence the various numberings of the B vitamins. Some of the materials thought to be separate vitamins were found on purification and accurate analysis to be identical to others already given a letter. These were then eliminated. Hence there is no vitamin F or G.

Vitamins are used in very small quantities by our bodies and help to make other materials needed for healthy living. Vitamins are of two types:  those that are fat-soluble or water-hating (hydrophobic) (A, D, E and K);
those that are water-soluble (B and C). The water-soluble ones have polar, water-loving (hydrophilic) groups in their structures, e.g. O H groups.
The fat-soluble vitamins can dissolve in the fats of our bodies, in which they can be stored. Too large a concentration of these can lead to an illness called hypervitaminosis. Seal livers, for example, are extremely rich in vitamin E. This makes them toxic if eaten in too large a quantity by most people. The metabolism of the Inuit people, who eat seal liver, has adapted to cope with this. The water-soluble vitamins cannot be retained in the body for long periods. They are flushed out and excreted and so must be constantly taken in by eating fruit and fresh vegetables.

‘Grandma Dushi has developed a few patches of discoloured skin on her face and arms. I hope it is not catching!’ In more recent times Britain, being in northern latitudes, has had an influx of residents from more sunny areas such as the Caribbean and Asia. In some instances the colour of their skin (developed to protect them from very hot sunshine) has prevented them absorbing enough sun through the skin to effectively make enough vitamin D. In these cases the patients are given diets and supplements to try to overcome this deficiency and the resulting skin discolouration.