B12 loading injections

[B12_crohnie]

Hi there, just wondering? I’ve had B12 deficiency since 1983. (Total non absorption due to Crohn’s surgery) My last loading dose of B12 was in 2001 followed with the usual 12 weekly maintenance (now down to 8 weekly).... does the maintenance dose maintain the levels of the ‘loading’ injections long term?... I’m guessing the B12 stores will deplete over the years and then rely solely on the maintenance injection to ‘keep going’....

Can anyone tell me what blood levels are first expected after the loading injections are completed - as the ‘starting point’ before this store then starts to deplete.

Thanks x

[Nackapan]

As I understand it you are totally reliant on what you put in. Whens it's used it needs more. Even if some Is stored you csn never use it as you cant process it unless its straight into your blood stream.

As for numbers mine was done as folate was done at the same time in the lab. It just said over top of the range .

So numbers dont mean anything.

On injections your levels hopefully will be kept high.

Go by how you feel.

[Gambit62 Administrator]

even if your stores are refilled from the B12 injections the mechanism for releasing them into the blood relies on the same mechanism as is used to absorb B12, which isn't functioning. (released from liver in bile to be absorbed in the terminal ileum), so any stores are a bit irrelevant. That means that you are left with the amounts in your blood as your store of B12.

After loading doses your B12 levels should be well over the top of the measurable range then they will drop over time.

On average Hydroxocobalamin is retained in the blood for 2 months but there is huge variation from individual to individual and actually an injection can produce a reaction in some people that seems to make the process that transfers B12 from blood to cells less efficient. As a result the normal range for serum B12 pretty useless as a measure of B12 sufficiency, which is why the BCSH guidelines don't recommend repeated testing after loading doses.