Water- and fat-soluble vitamins are essential for human and animal nutrition. Several of them are produced in amounts of well above 1000 t annually worldwide. In this highly competitive field, catalytic methods represent ideal tools to lower production costs, and consequently gain an economical advantage, by the application of environmentally benign processes. Examples of industrially important transformations given in this review are grouped by reaction types, e.g. hydrogenation, oxidation and various alkylation, rearrangement, cycloaddition, and esterification reactions. (C) 2004 Elsevier B.V. All rights reserved.