Prevalence of Vitamin B12 Deficiency Among Adult Male Outpatients in a Hospital Setting: A Retrospective Cross-Sectional Study at Hazm Mebaireek General Hospital, Qatar.

Introduction Vitamin B12 deficiency is a common nutritional deficiency, particularly among individuals with poor dietary intake or malabsorption disorders. Given the potential for serious health consequences-including anemia, neuropathy, and cognitive decline-routine vitamin B12 monitoring is critical, particularly in patients with chronic conditions. This study aimed to determine the prevalence of vitamin B12 deficiency and borderline deficiency in male outpatients attending a hospital clinic. Methods A retrospective cross-sectional study was conducted, including male patients attending outpatient clinics at Hazm Mebaireek General Hospital between April 1 and October 31, 2022. Serum vitamin B12 levels were measured, and patients were categorized into three groups: deficient (<150 pmol/L), borderline deficiency (151-221 pmol/L), and adequate (≥222 pmol/L). Descriptive and statistical analyses were performed to assess the prevalence of deficiency and borderline deficiency. Results Among 1173 male outpatients, 13.2% had vitamin B12 deficiency, and 23.8% exhibited borderline deficiency, totaling 37.0% with suboptimal B12 status. A higher prevalence was observed among South Asian participants, suggesting dietary influences. Conclusion Vitamin B12 deficiency and borderline status are common among male outpatients attending medical outpatient clinics, especially among South Asian expatriates. Routine screening in high-risk groups may prevent irreversible complications and should be considered in national guidelines.