Comparison of the Oral Absorption, Distribution, Excretion, and Bioavailability of Zinc Sulfate, Zinc Gluconate, and Zinc-Enriched Yeast in Rats

Mol Nutr Food Res. 2018 Apr;62(7):e1700981. doi: 10.1002/mnfr.201700981. Epub 2018 Mar 8.

Abstract

Scope: The oral absorption, distribution, excretion, and bioavailability of zinc sulfate (ZnS), zinc gluconate (ZnG), and zinc-enriched yeast (ZnY) in rats are fully and systemically compared for the first time.

Methods and results: After zinc compounds were orally administered to rats at a single dose of 4 mg Zn kg-1 , blood, tissues, urine, and feces at different time points were collected for the quantification of zinc concentration. Blood was also harvested for the zinc assay in the multiple-dose administration. Plasma zinc levels among three zinc compounds showed no difference, and zinc was widely distributed in various tissues with the level sequence of bone > liver > pancreas > testes. The net Zn balance was 2.993, 5.125, and 7.482% for ZnS, ZnG, and ZnY, respectively.

Conclusion: ZnS, ZnG, and ZnY show equivalent bioavailability based on plasma and tissues zinc levels, although ZnY was statistically more absorbed and retained than ZnS and ZnG based on the excretion amount.

Keywords: absorption; bioavailability; distribution; excretion; zinc-enriched yeast.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bone and Bones / metabolism*
  • Dietary Supplements*
  • Feces / chemistry
  • Femur
  • Gluconates / administration & dosage
  • Gluconates / metabolism*
  • Intestinal Absorption*
  • Intestinal Elimination
  • Kinetics
  • Liver / metabolism
  • Male
  • Nutritive Value
  • Organ Specificity
  • Pancreas / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Renal Elimination
  • Testis / metabolism
  • Yeast, Dried / administration & dosage*
  • Zinc / analysis
  • Zinc / blood
  • Zinc / metabolism*
  • Zinc / urine
  • Zinc Sulfate / administration & dosage
  • Zinc Sulfate / metabolism*

Substances

  • Gluconates
  • Zinc Sulfate
  • Zinc
  • gluconic acid