An extensive literature review discusses the effect of nutrient intakes on the action of non-nutrients, and vice-versa. The topics are arranged in 28 nutrient sections which can contain up to 17 non-nutrient groups. Included are a synopsis of the actual status of research; generalizations; and directions for future research. Humans must incorporate nutrients for optimal health; but non-nutrient substances are being ingested, either voluntarily (smoking), intentionally (drugs), or unconsciously (air, water, and food). The quantitative relationship between non-nutrients and health are seldom known; this review attempts to draw conclusions regarding their influence on nutritional status. Special attention is paid to: changed action or toxicity of non-nutrients in altered nutritional situations (malnutrition), side effects of intake of non-nutrients on nutrient metabolism (nutritional requirements); and nutrient influences on the activities of non-nutrient-metabolizing enzymes (especially hepatic microsomal enzymes). An extensive bibliography of 896 references is included. (kbc) Journal Title: World review of nutrition and dietetics. Journal Volume/Issue: 1977. v. 26 Main Author: Oltersdorf, U. Other Authors: Miltenberger, R., Cremer, H.-D.