ABSTRACT
Tracer methodology allows one to follow the fate of a mineral into the food supply or the absorption and metabolism of the mineral upon consumption or introduction into body pools of animals or humans. However, our understanding of human nutrition is deficient because of ethical constraints to study those processes with radioisotopes in humans. Stable isotopes have begun to be used in the 1980s by mineral nutritionists to fill in this gap of knowledge. Stable isotopes are much more difficult to analyze than radioisotopes. Numerous studies on the absorption of minerals by humans and animals using both radioisotopes and stable isotopes have been reported. A detailed discussion of intrinsic labeling methodology for plant foods is given by Weaver. As for plants, the ultimate goal is to produce tissue in which the isotopic tracer has been deposited in the same manner as the endogenous mineral.
