Vitamin B₁₂ Therapy in Older Adults and Misconception of Its Inappropriateness

To the Editor: Based on their study combining registry data of serum B₁₂ measurements and prescriptions of B₁₂ injections, Silverstein and colleagues¹ recently claimed that 64% of elderly patients receive inappropriate B₁₂ injection treatment. Their article presents a general misconception of B₁₂ deficiency and its treatment. The study included 146 850 patients with a prescription of B₁₂ injections; B₁₂ deficiency was defined as serum B₁₂ 221 pmol/L or less, but the authors fail to acknowledge the well-documented limitations in the use of this biomarker for diagnosing B₁₂ deficiency.^2,3