Oral zinc tolerance test in pregnant women

Zinc (Zn) is essential for fetal growth and development, and Zn requirement is increased during pregnancy. The purpose of this study was to determine whether intestinal Zn absorption is increased during pregnancy in order to maintain Zn homeostasis. Oral Zn tolerance test (ZnTT) wax performed on 25 healthy pregnant women and 7 healthy nonpregnant female volunteers after the administration of 22.5 mg elemental Zn as sulphate following an overnight fast at a single oral dose. Although the mean baseline plasma Zn level was lower in pregnant women than the controls (P < 0.05), there was no statistically significant difference in Zn absorption as determined by the 2nd- and 3rd-hour plasma Zn levels. The relative dose responses also did not show a significant difference between the pregnant and the control groups. Furthermore, different trimesters and the nutritional status did not have a significant impact on Zn absorption. The results suggest that the lack of a compensatory increase in intestinal Zn absorption in spite of the low Zn status in pregnancy may suggest the intestinal factor as a contributary factor in poor bioavailability. J. Trace Elem. Exp. Med. 14:17-23, 2001. (C) 2001 Wiley-Liss, Inc.