An Analysis of Vitamin B12 Levels in Patients Admitted to the Internal Medicine Ward Over the Past Five Years and Their Relationship with Admission Diagnoses

Introduction: Vitamin B12 is an essential micronutrient involved in various metabolic processes, including DNA synthesis and neurological function.B12 deficiency can lead to significant hematological and neurological disorders.This study aimed to evaluate changes in serum vitamin B12 levels in patients admitted to the internal medicine department over the past 5 years and examine their relationship with admission diagnosis.Methods: This retrospective study included 500 patients hospitalized in the Internal Medicine Department at University of Health Sciences Turkey, stanbul Training and Research Hospital between January 2020 and 2024.Patient data were obtained from the hospital information system and categorized according to demographic variables, reason for hospitalization, chronic diseases, vitamin B12 supplementation, metformin use, and serum vitamin B12 levels. Results:The study cohort comprised 500 patients with a mean age of 63.1 years.No significant differences in B12 levels were found between different age groups or genders, nor across the years studied.However, patients hospitalized for pancreatitis and those using metformin had significantly lower B12 levels (p<0.05),whereas patients in palliative care or those with malignancies had significantly higher levels (p<0.05).The use of vitamin B12 supplements was correlated with significantly higher serum B12 levels (p<0.05). Conclusion:The serum vitamin B12 levels of patients admitted to the internal medicine department remained stable over the past 5 years.However, certain subgroups, such as patients with pancreatitis, malignancies, and metformin use, exhibited significant variations in B12 levels.Regular monitoring of B12 levels in high-risk groups, such as patients with diabetes receiving metformin, is recommended to prevent deficiency-related complications.Elevated B12 levels in patients with cancer should prompt further investigation into the underlying malignancies.