Elevated Serum Vitamin B12 Concentrations Are Nonlinearly Associated with Cancer Incidence and All-Cause Mortality: A retrospective analysis of the global multi-institutional cohort study.
BACKGROUND Serum vitamin B12 is among the most frequently ordered laboratory tests, and both low and high concentrations have been linked to cancer and mortality. However, the full dose-response shape and the contribution of reverse causation remain unclear. OBJECTIVE We aimed to characterize the dose-response shape...