COMPARISON OF ABSORPTION OF 5 ZINC PREPARATIONS IN HUMANS USING ORAL ZINC TOLERANCE-TEST

Several pharmaceutical preparations of zinc salts are currently in use as nutritional supplements and as therapeutic interventions for certa in diseased states including macular degeneration. However, their clin ical efficacy as judged by their absorption has not been properly docu mented. In this study, we have compared the absorption of zinc for zin c acetate, zinc oxide, zinc sulfate, zinc aminoate, and zinc methionin e by the use of the oral zinc tolerance test. Six females and four mal es between the ages of 51 and 66 years volunteered for this study. The same subjects received different capsules at 2-week intervals. Change s in plasma zinc levels (mug/dl), percent of changes in plasma zinc, a nd area under curve generated by percent change in plasma zinc followi ng the oral tolerance tests were analyzed statistically. Under the con ditions of our experiments, zinc oxide was least absorbed. In our clin ical experience, zinc acetate is the best tolerated zinc preparation, and it showed one of the highest levels of absorption after oral intak e in this study. (C) 1993 Wiley-Liss, Inc.