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Interest has recently centered on selenium in the diet. Ivan Sharman PhD, FRSC, describes its discovery, its association with vitamin E, its likely role and dietary sources of the mineral

Recent advances in multi‐element analyses of biological samples by techniques, such as neutron activation and atomic absorption spectroscopy, have aroused interest in a variety of trace elements that have not generally been recognised as nutritionally essential. Such an element is boron: suggestions that this may be important in human dietary are considered by Ivan Sharman PhD, FRS

The subject of nutrition and athletic performance is by no means a recent one. In those far off days of the first Olympic Games held in Greece from 776 BC‐400 AD the athlete was concerned with what he ate. The first competitor whose special diet we are told anything about was Charmis of Sparta. He was victor of the sprint race at the Games held in 668 BC and is known to have trained on a diet of dried figs. Tradition indicates that as a sprinter he found the extra sugar in fruit helpful. Later, Dromeus of Stymphalus, a trainer who won the long race in 460 and 456 BC introduced a ‘meat’ diet which rapidly became popular.

Professor H. M. Evans, when making a study of the reproductive capacity of rats at the University of California in 1922, found that animals given a diet containing all the then known vitamins failed to produce normal litters. This observation indicated that another vitamin was required for fertility and subsequently led to the recognition of vitamin E. The vitamin was known to be present in lettuce and wheat germ, since when either of these were added to the rats' feed their fertility was restored. Subsequently, in 1936, by a lengthy procedure for concentrating the vitamin, Evans was successful in isolating the pure substance from wheat germ oil. It was identified as an alcohol with the chemical formula G29H50O2 and found to be fat soluble. At the suggestion of Professor G. Calhoun, Evans introduced the name “a‐toco‐pherol” for the pure compound (from the Greek tokos = childbirth, phero = to bear, and “‐ol” indicating that the substance is an alcohol).

It is well known that the human body requires many different nutrients for its growth and healthy maintenance. Some nutrients are required in relatively large amounts, namely the carbohydrates, fats and proteins, whilst others are needed only in small amounts. The latter include the vitamins, minerals and trace elements. The requirement of each different nutrient has been ascertained with a reasonable degree of accuracy for the varying ages and types of mankind. For optimal health the requirements of each nutrient have to be met in the food eaten by every individual.

So it was that St Paul, who knew a great deal about athletics, advised his correspondents in Corinth nineteen hundred years ago but the advice might equally well be given to‐day. Every athlete knows the importance of exercising his body in training but may overlook the contribution that an appropriate diet may make to his performance.

In 1987 the Medical Research Council's Dunn Nutrition Unit celebrated its Diamond Jubilee.1 What was the background to the Council setting up a Nutrition research establishment in 1927? Why was Cambridge chosen and why is it called the Dunn?

Potassium, like sodium, is essential for the normal physiological functioning of the body. Both these elements are chemically very similar but in the body sodium is present in the free fluids whereas potassium is mainly in the fluids within the cells, for example, in the muscles and red corpuscles of the blood. Potassium has a complementary action with sodium in the functioning of cells and its concentration within any particular cell is closely controlled.

Pyridoxine (Vitamin B6). This vitamin has been shown to be an essential growth factor for all experimental and domestic animals so far investigated. It is also known to be required by human beings for the metabolism of amino acids including the conversion of tryptophan to nicotinic acid. Pyridoxine was first identified in 1934 as the factor in the ‘vitamin B2 complex’, distinct from thiamin and riboflavin that would cure a specific nutritional dermatitis in rats; it was designated vitamin B6. In 1936 the vitamin was concentrated by Birch and György. Soon afterwards it was isolated and synthesized.

Ever since historical records have been kept, salt has played an astonishingly important part in the lives of men. Wars have been fought over its sources, and for centuries its trade was more important than that of any other material. The salaries that we draw today are in direct lineal descent from the salt money paid to the Roman soldiers.