ABSTRACT
The efficiency of Zinc (Zn) absorption appears to be homeostatically regulated since Zn is used more efficiently at suboptimal levels and absorption is reduced when excessive levels of Zn are fed. The absorption of Zn is also increased during pregnancy and lactation. There are four distinct phases of Zn absorption, as outlined by R. J. Cousins, all of which may exercise some control in the overall utilization of Zn. These are the uptake of Zn by the intestinal cells, the intracellular control of Zn absorption, the transfer from intestinal cells to the portal circulation and the secretion of Zn into the intestine. The high content of phytic acid is probably an important factor responsible for the poor availability of Zn from sesame seed meal. Extracted bran fiber or the addition of a dietary fiber such as pectin had no effect on growth rate and food intake, suggesting that phytate rather than fiber is the major component influencing Zn availability.
