Running a B12 deficitwhich about six percent of Americans under the age of 60and 20 percent of those over 60 do (1)puts you at risk for muscle weakness, fatigue, depression, memory issues, erectile dysfunction, and a cluster of symptoms that can be so severe that theyre debilitating
Lugli GA, Calvete-Torre I, Alessandri G, Milani C, Turroni F, Laiolo P, Ossiprandi MC, Margolles A, Ruiz L, Ventura M
doi:10.1016/j.clnu.2017.07.008
However, these are typically associated with long-term mega-doses far exceeding whats in your weekly shot
NHS Guidelines on B12 Treatment and Weight Management The NHS follows NICE and British Society for Haematology guidelines for B12 deficiency management, which emphasise evidence-based diagnosis and treatment protocols
B12 breaks down foods into usable energy necessary for everyday tasks and activities