The Nobel Prize and the Discovery of Vitamins

In the course of the 19th century, chemists and physiologists studying the composition of foods and the nutritional requirements of humans and animals found that our diets needed to include the complex nitrogenous compounds called "proteins" (that, with water, form the bulk of our lean tissues), together with fats, starch and sugars that all provide usable energy during their oxidation in the body. It was also realized that bones contain high concentrations of lime (calcium oxide) and phosphate salts and the body, generally, has a variety of other necessary mineral salts, though it was felt that mixed diets normally supplied adequate quantities of all these without any need for special precautions.