Corrigendum: Biomarkers and Algorithms for the Diagnosis of Vitamin B12 Deficiency - Hannibal, Luciana; Lysne, Vegard; Bjørke-Monsen, Anne-Lise; Behringer, Sidney; Grünert, Sarah C.; Spiekerkoetter, Ute; Jacobsen, Donald W.; Blom, Henk J. (Frontiers in Molecular Biosciences, 2017)