Four weeks of weekly doses at 2.5mg fits perfectly within that window
Some of the treatments can be a quick fix and are only needed when the ailment is active ie: migraine, illness, post-workout or travel fatigue, etc
Sanmartin C, et al
Systematic review with dose-response meta-analyses between vitamin B-12 intake and European Micronutrient Recommendations Aligned's prioritized biomarkers of vitamin B-12 including randomized controlled trials and observational studies in adults and elderly persons
Tharappel JC, Cholewa J, Espandiari P, Spear BT, Gairola CG, Glauert HP: Effects of cigarette smoke on the activation of oxidative stress-related transcription factors in female A/J mouse lung
In some cases, its used before or after surgery to support the healing process