A brief review of the literature indicates that nutritional deficiencies have been shown to increase the absorption and toxicity of orally ingested lead and cadmium. Results from recent studies indicates that low level oral ingestion of cadmium and lead perturbs the metabolism of zinc, copper, and iron and that these changes may be the earliest manifestation of the toxicity of lead and cadmium. The significance of these findings reveals itself in two ways: namely, that toxicologic investigations of lead and cadmium, whether experimental or clinical, must be based on a definitive consideration of the nutritional status of animals or people, and, secondly, that the preventive role of nutrition, especially that of trace metal intakes, must be taken seriously when establishing measures for reducing, eliminating, or combatting the toxic effects of widespread exposure to lead and cadmium in humans.