Trace elements in foods: Zinc contents of raw foods—A comparison of data originating from different geographical regions of the world

Zinc is one of the most important essential trace elements in human nutrition. A zinc deficiency of the human body leads to several disorders, but an excessive zinc intake also causes various acute and chronic adverse effects. Therefore an adequate supply of zinc from food is a basic necessity, and the documentation of reliable quantitative data in several international food composition tables is of general interest. In this study, the zinc contents of selected raw foods, originating from different continents of the world, are compiled, and their variations are displayed. Representative foods for several food groups like milk, meat, fish, cereals, vegetables and fruits are discussed comparatively. Interestingly, we could posit a remarkable consistency in the amounts of zinc in raw foods, especially in edible animal offal and some vegetable raw materials, deriving from European, Asian, African or American regions. The contamination of soils, such as that caused by metal processing industries, is significantly influencing the zinc concentration in plants. The standard of knowledge concerning the forms and mechanisms of the molecular binding of zinc in animal and plant tissues is summarized.