VDR and type 1 diabetes mellitus: Finally, Habibian et al. [134] showed that sufficient serum 25(OH)D levels (≥30 ng/mL) and certain genotypes of TaqI and BsmI SNPs in VDR were significantly associated with higher levels of stimulated C-peptide in patients with new-onset T1D, potentially resulting in a greater preservation of residual beta-cell mass and function.