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recommendationchoosing-wisely· endocrinology / labs· item cwus-aace-004

Don't routinely test vitamin B12 levels in patients without symptoms or risk factors for deficiency. Setting: no symptoms (unexplained anaemia, neuropathy, cognitive change, glossitis) and no risk factors (metformin or long-term PPI use, vegan diet, malabsorption, gastric surgery) for vitamin B12 deficiency Why: Routine B12 testing in asymptomatic low-risk patients yields borderline results that trigger cascades without improving outcomes. Consider instead: test only when symptoms or risk factors for deficiency are present Source: College of American Pathologists (test-utilization module) (Choosing Wisely, US, null).