Cavalier E, Lukas P, Bottani M, et al. - Researchers estimated the biological variation (BV) and reference change values (RCV) of different bone metabolism biomarkers on a large, well-described cohort of individuals. In the European Biological Variation Study (EuBIVAS), this study included a total of 91 individuals from six European laboratories. They collected fasting blood samples weekly for ten consecutive weeks. There was no impact of gender upon the within-individual estimates. For bone markers, the EuBIVAS has served updated BV estimates, involving iFGF23, which have not been previously published, facilitating the improved follow-up of individuals being treated for metabolic bone disease.