Medical Hypotheses 20: 17-27, 1986 A RE-EVALUATION OF NUTRITIONAL GOALS – NOT JUST DEFICIENCY COUNTS

There is considerable controversy about the soundness and relevance of so-called "megavitamin" therapy for various illnesses. In this article it is suggested that this disagreement is caused to a large extent by the use of two very different approaches to nutrition, which are referred to here as the "nutritional need" and "optimal intake" approaches. It is clear that a re-evaluation of the goals of nutrition is required, as nutritional recommendations deal mainly with the prevention of deficiency diseases and are not concerned with optimal levels of intake. THE NUTRITIONAL NEED APPROACH Originally some deficiency diseases, such as pellagra and beri-beri, were thought to be infections. Typically, classical infectious diseases are all-or-none diseases: either a person has pneumonia or they do not. Deficiency diseases were thought to be of a similar nature, i.e. it seemed as if a person was either affected by a deficiency or they were not. Although the cause of deficiency was subsequently found to be different, the all-or-none conception still remained. In this all-or-none description of deficiency, "nutritional need" is the critical daily intake which divides the two states of health: sick and well. Thus nutritional need corresponds to the smallest amount which prevents deficiency. This conceptual framework leads to the attitude that, when there is no obvious deficiency, no benefit can be derived from increased amounts of essential nutrients. The all-or-none notion of deficiency is widely accepted, at least implicitly. For example, it is assumed in Recommended Dietary Allowances (RDA) (1). In these recommendations nutritional need is used as a basic concept, yet no attempt is made to examine its full implications. The assumption of the all-or-none nature of deficiency is, however, an oversimplification of the effects of nutrients on the body. A severe deficiency is only a pre-morbid condition with an