Pernicious Anaemia Society
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How long for B12 level to rise


Without telling my whole story, I found out my B12 was 143 this past July 2017. I have been getting injections monthly since then (weekly for the first bit). I sometimes would feel very energetic but lately (the past month) I've been really tired and weak and my left arm is going numb and tingly again. By the way, my iron has been low forever too but I take supplements & folic acid as well. I have a long story of all my issues but I just want to know when my B12 will be normal again.


3 Replies

Your serum levels of B12 will, almost certainly, be way above 'normal'.

However, as many of us here will testify, serum levels can be totally meaningless.

You are stuck in a familiar dilemma where you need to increase the amount of B12 in your body. Successful solutions include:

Persuading your doc to increase the frequency of your injections. This should be your first choice, but it rarely works.

Take additional supplements in the form of sublingual sprays or lozenges. Some people have great results, others find they do nothing.

Try self-injecting. A lot of hassle, but the best way to reach an optimal solution.


Are you in US? I ask because weekly and then monthly injections sounds like US treatment protocol.

Has you doctor done any testing for "root" cause of your b12 deficiency?

You mentiin your iron has been low forever. So my question is...Do you have h pylori?

I had/have h pylori (first positive Aug 2017) without any of the stomach pain or heartburn that is largely associated with it. My symptoms were nausea and feeling full quickly.

I was given the treatment and waited 3 months for my body to heal and feel better, which it didnt, so i tested again in Nov 2017and was still positive.

I went through second treatment with different antibiotics and need to wait the 8 weeks before being tested again to see if it is gone.

If you are in US you can get straight b12 injections at some weight loss clinics. Most clinics only suggest their weight loss injections which only have about 300 micrograms of B12. But some clinics offer straight B12 injections which have 1000 micrograms of B12. My injections cost $15 and they will only give them to me once a week.

Best of luck


My serum levels rose rapidly but my symptoms worsened as others erupted. I was then referred to my neuro who wants me to have an brain MRI because he insist should not still be having symptoms if due to lack of b12. I, in turn researched my symptoms and found some mimics of b12 def can be ms and lyme to name a couple. I do have gastritis which could of caused my issues but wonder what caused that? I await h pylori results but learned that lyme symptoms cause the joint pains which started in my knees may years ago. I heard that experimenting with natto can be indicative of lyme also. I was thinking that maybe I had an autoimmune but remember that cortisone severely worsened my symptoms. Prolonged worsening symptoms must be examined...


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