Silverstein WK, et al. - Since no published literature identifying prescribing patterns of intramuscular B₁₂ using laboratory data to record individuals' serum levels could be figured out, thus, in this study, experts evaluated the prevalence of irrelevant B₁₂ supplementation via population-based databases and assessed the related cost. Randomized clinical trials illustrated that in comparison with intramuscular injections, treating vitamin B₁₂ (cobalamin, or hereinafter B₁₂) deficiency with oral supplementation considerably raised serum B₁₂ levels, with no variation in hematologic or neuropsychiatric outcomes. Irrespective of this, a few primary care physicians still inaptly administer B₁₂ injections to the old population.