The clinical utility and cost-effectiveness of routine vitamin B12 screening in adult psychiatric patients.

Background: Diagnosing and treating vitamin B12 deficiency in psychiatric populations is important, but the justification for routine screening in patients without risk factors or physical findings remains uncertain, especially in resource-limited settings. Aim: This study aimed to assess the clinical utility and cost-effectiveness of routine vitamin B12 screening in adult psychiatric inpatients. Setting: The study was conducted at Townhill Hospital, a tertiary psychiatric facility in South Africa. Methods: A retrospective chart review was performed for the period 01 July 2021 to 31 December 2022. Data collected included demographics, clinical diagnoses, medications, risk factors for deficiency, vitamin B12 test results, associated costs, and clinical responses to abnormal findings. Results: Of 366 patients (168 male, 198 female; mean age 35.95 ± 13.44 years), the mean serum vitamin B12 level was 423.86 mmol/L (SD ± 233.37), with a median of 359 mmol/L. Vitamin B12 deficiency was identified in eight patients (2.2%). The cost per deficient patient was R5780.73. Statistically significant associations were found between low B12 levels and pregnancy, vegetarian diet, abdominal surgery, and metformin use (p < 0.05). Only half of the deficient patients received replacement therapy. Conclusion: Routine vitamin B12 screening in the absence of physical findings or known risk factors is not clinically or economically justified. Targeted screening should be considered to optimise resource use and patient outcomes. Contribution: In resource-constrained environments, prioritising high-yield interventions is essential to improving care efficiency.