Is this Garbage or truth?

[WorkingProgress]

Cobalamin therapy details.

The 1000-μg dose begins repletion of stores (up to 150 μg is retained from that injection by most patients).

The question is how much is retained by the body from a single 1000mcg injection.

Is injecting less better if you suffer too many sides from 1000mcg so why not inject 200mcg if only 150mcg is actually retained?

Is there a declining percentage ratio from dose to retention? ???

eg) 150mcg 100% retained

200mcg 75% retained

300mcg 50% retained

There is so much MESS on this topic I am confused.

[Nackapan]

I dont think it's actually known. I don't even know how the 1mg doses started.

It was hoped to stay thr system circulating until used. Snd thd rest expelled via urine

Originally the b12 injections were given more frequently.

Thats why levels have to be kept high once on injections as only can uses available in your blood. Some is not able tk be used as not active.

It might reach your liver but yoh csnt utilises it .

I often think a slow trickle woukd be better. Or slow release lije they do with insulin. Short and long term acting to give a bases over night.

I initially thought you would store it once replenished then topped up.

Thus isn't the case but irs what we are bring told by gps.

Om as confused as you really still.

I think I've read too mich conflicting stuff .

Very difficult with no clear medical guidance or understanding.

My friend a retired Gp thought it was a quick fix and was shocked my b12 level and that it had not been tested before.

Also thinks j do not need such frequent injections??

When j try snd explain yo him j realises I'm not crystal clear.

But how csn we be egrn so much is unclear sbd no definitive test fo PA .

Akso clinical skills being lost.

The Dutch doctor who has given lecturesfor PAS is a good source .

Other stuff is rubbish.

[WorkingProgress in reply to Nackapan]

I hear you. Well I shall inject less and see my reactions, healing and sides. It is a hugely misunderstood topic especially in the medical profession.One thing is for sure is that we are not making this up. We are suffering.

[Gambit62 Administrator in reply to Nackapan]

1000mcg was selected as the dosage that was likely to be most effective given that the rate at which the body removes excess is higher if the serum B12 levels are higher.However, it may not be the best dosage for everyone given that its based on averages and we know that averages don't necessarily describe a particular individual - especially when there is as high a degree of variation in people's responses with B12.

[WorkingProgress in reply to Gambit62]

You are correct it is very individual and one's tolerance has to be taken into consideration. We do not want to add in any more discomfort. After all if you are SI then you can trial and error your dose and frequency .

[Gambit62 Administrator in reply to WorkingProgress]

However, in mind of your ealier post it would be better not to try and reuse art of an ampoule - just use part and discard.

[fbirder]

The pharmacokinetics of B12 are very complicated.

A 1000 mcg injection is slowly diffused from the injection site into the bloodstream. How slowly will depend on a lot of factors (exactly where in the muscle or fat the dose was deposited, how much fat the person has, etc.).

As the concentration in the blood increases it will get closer to the tubule reabsorption capacity. Let me try to explain -

When blood passes into the kidney, most of the fairly small molecules are filtered out. This filtrate is sent flowing down the kidney tubules, where all the stuff that the body wants to keep is reabsorbed, leaving just the unwanted waste (and enough water to dissolve it) to go out in the urine.

But the reabsorption of B12 has a limited capacity. Once the amount in the blood starts getting close to that limit more and more B12 is excreted in the urine. But that limit is different for different people.

At the same time some B12 is going into the tissues, where it needs to be used and other B12 is getting stored - mostly in the liver, but also other tissues.

So, if your injection gets absorbed quickly then the amounts in the blood will be over the capacity for reabsorption before it gets a chance to be stored. So more will go out in the urine.

The whole thing is far too complicated to make any sort of prediction.

You might retain 150 mcg from a 1000 mcg injection. I might retain 50 mcg and my friend might retain 400 mcg.

And it's not linear.

So if you can absorb 150 mcg from a 1000 mcg injection, it doesn't follow that you'll absorb 100 % of a 100 mcg injection.

[WorkingProgress in reply to fbirder]

Got it. Thank you. It's a feel it, test it, try, and assess and reassess to find what works best for you. Again we are all thankful for your brilliant informative answers. You should train GP'S on PA Anaemia and B12.

[Budsa in reply to fbirder]

That is an excellent and extremely clear answer fbirder.

[Gen89 in reply to fbirder]

Do you know on average how long it takes to absorb the b12 from the injection site into the blood stream ? Do you think it would be days or weeks?

[fbirder in reply to Gen89]

i think it averages about three hours.

[Cherylclaire Forum Support in reply to fbirder]

Yes, a very good description. And then of course, to complicate things further, it won't be the same every time.

We've all had those odd injections that felt like they did nothing.

[Gen89]

Great. Thanks for your reply.