Accuracy of three automated 25-hydroxyvitamin D assays in hemodialysis patients

► Not all automated 25(OH)D assays are equally accurate in hemodialysis patients. ► 25(OH)D measurements on Architect (Abbott) deviate most from ID-XLC-MS/MS. ► Architect falsely assigns 48.5% of hemodialysis patients a low vitamin D status. ► Method validation data in normal sera cannot be considered universally relevant. ► Matrix interferences may affect 25(OH)D testing in hemodialysis patients.