The semantically inclined will, no doubt, perceive an element of inconsistency in the title of this contribution. Any food(stuff) ingested for a nutritional purpose is, it could be argued, ipso facto a dietary component. To refer to “nonfood dietary supplements” would, therefore, be meaningless.

On the other hand, foods are often defined in traditional– historical terms, and it is apparent that there are a substantial number of “nutritionally significant” substances which, although not ordinarily components of a diet, may nevertheless be ingested in special circumstances. Whether such “foreign” substances are then described as food(stuffs) or as dietary nonfood(stuffs) is very much a matter of opinion.

The issue is further clouded by a tendency to regard foods as being of natural origin, whereas certain dietary supplements, although having a clearly definable nutritional role, may nevertheless have a “nonnatural” (synthetic) origin. And whereas “true” foods are rarely challenged in terms of potential toxicity, this is not the case with supplements – as evidenced, for example, by the American report on the safety of amino acids used as dietary supplements (Anderson, Fisher, and Raiten 1993).

Again, one must distinguish between nonfoods as dietary supplements and nonfoods as dietary components. Geophagists, picaists, and drug addicts may, in certain circumstances, ingest large amounts of nonfood materials, but these fall outside the scope of this discussion. Supplementation implies that the additional material is introduced intentionally for an avowedly dietary reason and is a substance that could not, in normal circumstances, be supplied by realistic dietary manipulation.