New aspects on trace element metabolism disturbances in man and pet animals

Considering the biological and clinical consequences of trace element distu rbances, more attention should be devoted to trace element metabolism and s tatus in humans and animals. In humans, trace element intakes and status ar e frequently marginal in large segment of the population, resulting in an h igher risk of nutrition-related diseases. Regarding the essential protectiv e roles of zinc and selenium against oxidative damage and decline of immune functions, or the beneficial effects of chromium on glucose tolerance, the re is now increasing evidence that appropriate supplementations, restoring marginal trace element status, could reduce in human the risk of degenerati ve diseases, and, in animals could participate to the improvement of functi ons like reproduction, immunity, or vision and taste. Surprisingly, little information is available concerning the real mineral requirements of pets a nd additional research also needs to be done to evaluate the efficiency of supplementations. Numerous questions need to be answered about the nature a nd forms of supplementation, the doses administrated and the duration. Inte rpretation of the studies is also often limited by, mainly, use of inapprop riate indicators of status. Most of the reported parameters reflect biologi cal modifications and few studies focused on clinical or functional signs, such as number of infections, overall health or incidence of diseases. The objective of this paper is to review what is currently known about trace el ement biological functions, assessment of the status and biological and cli nical consequences of trace element metabolism disturbances in man and anim als. Recent supplementation trials and their possible beneficial effects wi ll also be evaluated.