The markers s-OC, s-CTX, u-PYR, u-DPD are likely not to differ over time (Miazgowski and Czekalski, 1998; Mastrandrea et al., 2008; Hamilton et al., 2012), suggesting that bone turnover does not change over time in T1D and support the hypothesis that bone turnover is lowered during puberty, since none of the available longitudinal studies have investigated a young T1D population. Here, CYP27A1 is linked to type 1 diabetes mellitus.