Prevalence of Vitamin B12 Deficiency Among Patients Presenting With Neuropathic Symptoms: A Retrospective Cross-Sectional Analysis

Background: Vitamin B12 deficiency is a well-recognized and potentially reversible cause of peripheral neuropathy. Patients presenting with neuropathic symptoms are frequently evaluated for metabolic and nutritional causes; however, the burden of vitamin B12 deficiency in this population remains under-reported in routine clinical practice. Objectives: To determine the prevalence of vitamin B12 deficiency and describe its association with clinical and laboratory characteristics in patients presenting with neuropathic symptoms. Methods: This retrospective cross-sectional study was conducted at a tertiary care hospital and included adult patients who presented with neuropathic symptoms between January 2022 and December 2023. Based on an assumed prevalence of vitamin B12 deficiency of 30% among patients with neuropathic symptoms, a confidence level of 95%, and an absolute precision of 6%, the calculated minimum sample size was 224 patients. Demographic details, clinical presentation, comorbidities, and laboratory parameters including serum vitamin B12 levels were extracted from medical records. Vitamin B12 deficiency was defined as serum levels