The broad objective of this proposal is to define the changes in zinc absorptive capacity during human pregnancy and lactation and to determine if this capacity is influenced by maternal zinc status or maternal iron therapy.
Specific aims are: to determine longitudinal changes in zinc absorption from pre-conception across pregnancy and to determine if any changes are a specific effect of pregnancy, rather than secondary to changes in zinc status, by comparing the absorptive capacity of women who receive a daily zinc supplement of 10 mg with that of non- supplemented women; to determine if therapeutic iron supplementation diminishes absorptive capacity in the third trimester of pregnancy by means of a cross sectional study at 34 wks gestation; to determine if lactation is associated with longitudinal changes in zinc absorptive capacity and whether any changes are influenced by a 15 mg zinc supplement each day. The results of these studies will determine the extent to which the additional zinc needs of pregnancy and lactation can be met without increasing the dietary intake and will help towards defining dietary requirements for zinc during these important stages of the life cycle. They will also show whether iron therapy during pregnancy compromised zinc absorption. Apparent zinc absorption will be calculated from the difference between the amount of 70 zinc, a stable zinc isotope, given orally 10 hrs after last eating and the amount excreted in the feces. Zinc isotope ratios will be measured by fast atom bombardment mass spectrometry.
| King, J C; Hambidge, K M; Westcott, J L et al. (1994) Daily variation in plasma zinc concentrations in women fed meals at six-hour intervals. J Nutr 124:508-16 |
| Miller, L V; Hambidge, K M; Naake, V L et al. (1994) Size of the zinc pools that exchange rapidly with plasma zinc in humans: alternative techniques for measuring and relation to dietary zinc intake. J Nutr 124:268-76 |
| Wallock, L M; King, J C; Hambidge, K M et al. (1993) Meal-induced changes in plasma, erythrocyte, and urinary zinc concentrations in adult women. Am J Clin Nutr 58:695-701 |
| Sian, L; Hambidge, K M; Westcott, J L et al. (1993) Influence of a meal and incremental doses of zinc on changes in zinc absorption. Am J Clin Nutr 58:533-6 |
