Vitamins

Abstract

In a book devoted to a discussion of drugs and drug effects it may, at first glance, be surprising to find a group of physiologic substances like the vitamins. Originally vitamins were regarded as nutritive elements rather than as drugs or drug-equivalent compounds. We feel, therefore, that it is very important to reevaluate the position of the vitamins within the class of biologically active substances. The vitamins comprise a group of widely different chemical compounds and because of this variety, are somewhat difficult to define comprehensively. So far, the most generally accepted definition of vitamins is that given by Folkers (1969): “A vitamin is an organic substance of nutritional nature, which is present in low concentration as a natural component of enzyme systems and catalyzes required reactions, and may be derived externally to the tissue or by intrinsic biosynthesis.” To this definition it should be explicitly added that the intake of vitamins is essential for the maintenance of life and the well-being of the individual. In a book dealing with drug allergy in general and in a chapter presenting a discussion of allergic reactions to vitamins in particular, it is important to appreciate the dichotomy of the vitamins primarily as essential nutritive factors and only secondarily as drug-equivalent compounds. This feature clearly separates the vitamins from all of the other compounds discussed in this volume, which have no relation at all to nutrition in the sense the vitamins have.