Plasma zinc but not the exchangeable zinc pool size differs between young and older Korean women

This study was done to determine the effect of age on zinc metabolism and status among healthy Korean women. Measures of zinc metabolism and status were measured in eight young women (22-24 years) and seven elderly women (66-75 years) consuming a typical Korean diet. Oral and intravenous tracers highly enriched in (67)Zn and (70)Zn were administered simultaneously. Multiple plasma, 24-h urines, and fecal samples were collected after isotope administration. In the young women, additional plasma were collected to determine zinc kinetics using a seven-compartmental model. Exchangeable Zinc Pool (EZP) was estimated by Miller's method. Plasma zinc concentrations were higher in older women than younger women (p < 0.05). EZP and urinary zinc tended to be higher in older women than younger women. Fractional and total zinc absorption and endogenous fecal zinc losses did not differ between young and older women. A comparison of the zinc kinetics of the Korean and American women showed no differences in plasma or EZP zinc parameters. However, absorbed zinc and zinc flux to slowly turning over tissues (Q7) were lower in Korean women than that of Americans (p < 0.01) suggesting the total body zinc content of Korean women is lower than that of American women.