Vitamin B12 deficiency in older people: a practical approach to recognition and management

Vitamin B12 deficiency is common in older people and is linked to anaemia, cognitive decline, and dementia. Clinical presentation is variable, ranging from no symptoms or subtle, non‐specific symptoms, through to serious, irreversible neurological symptoms if left untreated. Although common, it is often under‐recognised, with diagnosis usually occurring on incidental blood test screening. Older people are at increased risk of vitamin B12 deficiency due to insufficient dietary intake, malabsorption associated with aged‐related changes in gastrointestinal function, higher incidence of pernicious anaemia, and chronic use of interfering medications such as metformin and proton‐pump inhibitors. Early detection and treatment in symptomatic deficiency are crucial to prevent irreversible damage. Vitamin B12 intramuscular injection bypasses potential absorption issues and is traditionally the first‐line treatment in older people. However, emerging evidence suggests that high‐dose oral replacement may be as effective. Older people often require lifelong therapy due to the irreversible nature of the underlying cause of deficiency. This review provides an overview of vitamin B12 deficiency and its management in older people.