Assessment of marginal zinc status in humans

The assessment of marginal zinc status is problematic. Currently, there is no universally accepted single measure to assess zinc status in humans. The development of a reliable measure of marginal or moderate zinc status woul d be useful for a variety of purposes. For example, a simple, yet sensitive and accurate measure of zinc nutritional status is critically needed to fu rther our limited understanding of the possible associations between zinc s tatus and the risk of developing various chronic diseases and in predicting favorable health outcomes in patient populations. A convenient and reliabl e zinc assessment tool is needed to identify subpopulations who are at a ri sk of zinc deficiency and as an objective guidepost to determine the need f or initiation of zinc supplementation or zinc fortification of the food sup ply, as well in the refinement of recommendations of dietary zinc allowance s. In frank zinc deficiency, clinical signs and static measures of zinc con centrations in a variety of readily available tissues, such as plasma, vari ous blood cell types and hair, may uniformly confirm the presence of deplet ed body zinc stores. However, in general, the relative insensitivity or imp recision of these measurements has resulted in general disappointment in th eir use to assess marginal zinc status. Therefore, the search continues to find a useful and reliable marker of marginal zinc deficiency. In an attemp t to speculate on possible future developments in the zinc status assessmen t field, a number of new and potentially promising approaches to this probl em are highlighted.