Oral zinc therapy in patients with supposed mild zinc deficiency--a critical review.

The importance of zinc in many processes of diseases remains unclear up today. Nevertheless many biochemical or clinical studies let support a high clinical relevance of trace elements especially zinc in the therapeutic concepts of diseases. Unfortunately the border between severe (or real) and mild (or subclinical) zinc deficiency is not clear defined. In addition methodical problems in determination of trace elements and misinterpretations of study results lead to unjustified assignment from several diseases in the group of zinc deficiency disorders. Another current problem is the consideration of bioavailability of oral commercial trace element products. Especially the regulation of zinc uptake in human under normal conditions and in case of zinc deficiency is not clear at this time. These problems let become tangled the actual literature for the clinical active physician at the field of zinc. In this mini review there is given an overview about published clinical studies with oral zinc supplementation in the past years.