B12 Hypervitaminemia: Pathogenetic Pathways and Clinical Implications.

Background. Pathological changes in vitamin B12 levels are a common laboratory finding. The increase in serum vitamin B12 levels is termed B12 hypervitaminemia, often perceived as a benign disorder, leading to its underestimation. Objective.This paper aims to examine the potential pathogenetic mechanisms and the association of vitamin B12 excess with various diseases. Methodology. A literature search was conducted using the PubMed, DOAJ, and Google Scholar databases. The search was focused on original articles, review papers, and reference lists published in English since 2000. Results. Increased vitamin B12 levels are encountered in hematological disorders, solid tumors, renal and hepatic diseases, as well as inflammatory conditions. Vitamin B12 supplements increase the levels and can exacerbate underlying pathological conditions. The pathophysiology involves disturbances in the biology and metabolism of vitamin B12 and its carrier proteins. Falsely elevated values can arise due to interferences in quantitative assays. Elevated vitamin B12 may represent an incidental finding, accompany findings of underlying disease, and coexist with manifestations of functional deficiency. Conclusion. Elevated vitamin B12 may serve as an early indicator for the diagnosis and monitoring of serious diseases. Understanding the underlying pathogenetic mechanisms and establishing diagnostic algorithms are crucial areas for future research. [ABSTRACT FROM AUTHOR]