Strontium isotope and concentration data from Iron Age – Roman Nijmegen and Heumen, the Netherlands

This dataset comprises strontium isotope ratios (87Sr/86Sr) and strontium concentration data from a maximum of 194 cremated human individuals (331 samples) excavated from 14 cemeteries in the Nijmegen region (the Netherlands), spanning the Iron Age and Roman periods. The sampling strategy prioritised the collection of multiple skeletal elements per individual. Where preservation allowed, samples were taken from long bone diaphyses, ribs, and teeth (dentine). Pars petrosa ossis temporalis samples were not available. The dataset accompanies the publication by De Coster et al. (submitted), which explores the impact of increasing urbanization and trade during the Roman period compared to the Iron Age. The findings indicate a trend toward reduced inter-individual variability in 87Sr/86Sr, likely reflecting a shift to a more homogeneous diet. This dietary change was possibly driven by a growing reliance on imported foodstuffs and increased salt consumption.