A typical protocol looks like this: Initial loading (for severe deficiency or pernicious anemia): Daily or every-other-day injections for 1 to 2 weeks, then weekly for 4 weeks Maintenance (pernicious anemia, ongoing absorption issues): Monthly injections indefinitely General wellness or dietary deficiency: Once every 1 to 3 months, depending on levels Your provider will check your B12 blood levels and recommend the right schedule for you
Stephen Gradus, Kathleen A
This makes injectable supplementation a reasonable approach for anyone with confirmed or suspected absorption problems, though it does not prove the combination provides benefits beyond separate administration
It is not a substitute for the official label, pharmacist counseling, prescriber instructions, or medical advice
Deficiency can occur in certain populations, including older adults, vegans, individuals with pernicious anaemia, those with malabsorption disorders such as Crohn's disease or coeliac disease, people who have had bariatric surgery or gastrectomy, and those on long-term medication such as metformin or acid-suppressing drugs