My b 12 level went from 168 to 475 after injections
My question is why do i till like I am on fire at night. Now I am not sleeping. Doctor prescribed trazedone, so I took it last night and I still tossed and turned. Is this just a symptom of the deficiency? I am at my wits end.
how many injections, over what period and how long after was the B12 serum test?
475 sounds a bit low for someone who has had B12 shots so may be that you are starting to be deficient again.
The serum B12 result doesn't really mean very much unless it comes back low after someone has been on shots. It only measures one part of the story anyway and that part of the story is going to be distorted by the shots anyway. Most of the B12 you have from a shot gets removed from you blood quite quickly - about 1/2 of it in the first 24/48 hours alone. However, the rate at which it is removed is very variable. A low serum B12 implies that your kidneys are quite efficient at removing the B12 but a high level doesn't say what is happening about transferring B12 from blood to cells where it is used so a high result doesn't mean everything is okay and that your cells are now getting the B12 they need.
What were your original symptoms and have you noticed any improvement - some people find it takes quite a while to notice a difference ... and for some people it can feel as if things get a bit worse before they start to get better - like the immune system goes into temporary overdrive so you notice infections a lot more as they clear ... and the aches and pains can get a bit worse as neurotransmitters start working properly again.
Did you just have the loading doses and then nothing for three months? If so then you probably aren't getting enough b12. It takes a consistently high level, (over 1000) to heal and reverse symptoms. It takes some time to get 'better', after all you did not become deficient over night, and the improvement is often slow. 475 is quite a low level for someone on injections and I would say that you need them more often.
My levels were about the same as yours in the same circumstances and I was in despair - til I researched and realised that's not high enough for me. Been SI every other day for 3 months and feeling more or less better! Only told the new GP after 2 months - check out all the info on here & go by how you feel not the levels in tests (mine now over 2,000). Good luck.
High B 12 but deficiency symptoms 
SIBO/ not SIBO ? Looking better, but still symptomatic
b 12 pro but no cons
