This is a serious problem, because doctors often agree to prescribe only a single shot every few months
Several factors influence injection site reactions
Effective when absorption is the issue
Direct Dosage: A single B12 injection often delivers a much higher dose directly into the system than a typical daily oral tablet, particularly when considering the limited absorption rate of the latter, contributing to their perceived and actual strength. However, for individuals with mild dietary deficiencies and no underlying absorption problems, high-dose oral B12 supplements (e.g., 1000-2000mcg daily) can sometimes overcome the need for intrinsic factor by allowing for a small amount of passive absorption, eventually raising levels, though this method is less predictable and slower than direct injection
Injections are advised to circumvent potential absorption challenges in the gastrointestinal tract, particularly for those with known issues like Crohn's disease or irritable bowel syndrome, providing a more immediate replenishment compared to oral supplements, which may not be fully absorbed
