Body weight-specific zinc compartmental masses in girls significantly exceed those reported in adults: A stable isotope study using a kinetic model

Maintaining optimal zinc status is important for normal growth and developm ent in children, but minimal data are available regarding zinc metabolism i n this age group. Our objectives were to utilize stable isotope-based compa rtmental modeling techniques to investigate zinc metabolism in healthy chil dren; to expand a current stable isotope-based model to include red blood c ell data; and to compare kinetic parameters in children with those previous ly reported in adults, Seven healthy girls, age 9.94 +/- 0.79 y, received 1 .1 mg of a (67)zinc-enriched tracer orally and 0.5 mg of a (70)zinc-enriche d tracer intravenous[y. Blood, urine and fecal samples were collected far 6 d. Stable isotope enrichments were measured by thermal ionization magnetic sector mass spectrometry. A six-compartment model based on a model previou sly reported in adults was used; the model excluded red blood cell data. Bo dy weight-corrected masses of the body zinc compartments derived using this model were significantly greater in children than those reported in adults . Modification of the model to include a red blood cell compartment increas ed the total identifiable zinc mass of the nongastrointestinal compartments by similar to 2.5%. We conclude that compartmental modeling can be used to describe zinc kinetics in children, and that the body weight-corrected zin c pool masses are significantly greater in children than in adults.