From edible clay to a clay-containing formulation for optimization of oral delivery of some trace elements: a review

Abstract

The present review describes the double beneficial effect of using clays for purposes of health and human nutrition: first, their chemical composition, which can enable the release of trace elements; and second, their mineralogical composition, which allows them to be used in the treatment of digestive diseases. The last part of the review is devoted to the release of trace elements contained in clay: clay-containing pellets designed for oral delivery of the trace elements iron and zinc. This multiple-unit pellet system is designed to be retained by flotation in the stomach cavity for a few hours (5 h), with simultaneous control of the release of the trace elements in order to optimize their gastrointestinal absorption. Finally, it is shown that the total amount of ions released from the clay was increased when the formulations were added, in comparison with raw clay, respectively as follows: Zn²⁺ (60% versus 40%), Fe³⁺ (70% versus 30%) and Fe²⁺ (95% versus 40%).

Keywords::

• Edible clay
• geophagy
• clay powder formulation
• trace elements
• gastrointestinal absorption
• floating pellets
• controlled release

Acknowledgements

The authors are grateful to Ms G. Magnusson for proofreading the manuscript.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.