Absurd: Will Supplemental Zinc Gluconate Deplete Your Zinc Levels?
Normally, I restrict myself to very recent studies, but the results of this 2007 ( Tompkins. 2007 ) study on the bioavailability of zinc-enriched yeast and zinc gluconate in healthy volunteers that recently resurfaced on the Mind&Muscle boards , is too counter-intuitive and, if not scientifically flawed, important not to make it into the news. In the study, which used a randomized, two-way crossover design, the volunteers were randomly assigned in groups of three to consume a single dose of either 20 mg of total Zn in the form of Zn gluconate or Zn yeast with 150 ml of water , after that urine, blood, and fecal samples were collected and analyzed over a 48-h period. The results were surprising, while " Zinc gluconate gave higher Zn concentrations in the blood in the first 6 h " it did not only show greater loss in the feces, but ... the net Zn balance after 48 h for Zn yeast was 9.46 but for Zn gluconate it was -2.00, indicating that Zn glucona...