Functional Implications of Vitamin B12 Deficiency

Vitamin B-12 deficiency is a common but underrecognized problem in older adults. Historically, B-12 deficiency was diagnosed once a severe pernicious anemia developed. Scientific developments have led to a new understanding of a broader spectrum of B-12 deficiency and identification of a milder form of deficiency associated with food/vitamin B-12 malabsorption. Using an individual example, this article describes the functional impact of vitamin B-12 deficiency and highlights modern approaches to diagnosis and treatment.