Minerals are essential for the maintenance of a wide range of metabolic functions in human beings, yet there is a lack of adequate information regarding their absorption, bioavailability and metabolism. Enriched stable isotopes provide safe, ethically acceptable and scientifically rigorous tools for investigating the metabolism of mineral nutrients in human subjects. Michrochemical and mass spectrometric techniques used for conducting human studies of the metabolism of essential minerals are described and discussed with reference to the precision of stable isotope ratio measurement normally required in these experiments. Specific examples are given, involving both single and double isotope labelling procedures. These include investigations of calcium and zinc absorption from different foodstuffs and a study of zinc metabolism aimed at the determination of body pool sizes. The convenience and precision of different mass spectrometric methods are discussed and stable isotope methodology is compared to radio-labelling techniques. Xeywordx Mass spectrometry; Calcium; Isotope ratio measurements; Mineral nutrients; Zinc