Studies on electrolyte and trace metal metabolism applying stable isotopes as tracers.

Tracer-kinetic investigations provide a useful tool for the assessment of body composition regarding electrolytes and trace elements. This paper demonstrates the feasibility of stable isotopes as tracers in studies on calcium and iron metabolism in risk groups like children. By applying both radioisotopes and stable isotopes simultaneously, in adults, a good intra-individual agreement was obtained for the derived figures of intestinal absorption. Using only stable isotopes, intestinal calcium absorption in children with renal failure was found to follow a similar pattern to that in adult patients.