I was diagnosed with a B12 deficiency at age 38. At the time of diagnosis, my B12 levels were in the 100s. My Internist gave me ONE shot and then put me on daily dose of B12 tablet. I had a hard time remembering to take the pills and thus my B12 levels remained below normal. We moved to 1 shot/month. Still, as of 8 weeks ago my B12 is around 300. Finally, after complaining of persistent exhaustion (14 months after initial diagnosis) my Internist prescribed 1 injection per week for 4 weeks, then wait 2 weeks and return to the lab for a blood test. My level as of a week ago is now at 451.
Given my result, she has prescribed 1 injection per month on an ongoing basis. I have asked her to please increase my prescription to 2x/month because I'm already feeling fatigued and had a noticeable boost in energy when I was taking 1 injection per week.
What are normal B12 reference ranges? If 4 injections has upped my B12 from 300 to 451, is that good? Will I be able to maintain good B12 levels on monthly injections?