Active b12 test

[Luac]

I am considering paying for an active b12 test. I self inject every other day - will a test be pointless?

Am I injecting active b12 or is the active element affected by what my body does with it?

Sorry if it is obvious.

[Hidden]

If you are self injecting as often as you are. The results will be sky high. What are you hoping to discover?

[Luac in reply to Hidden]

If the b12 is being used by my body. I was thinking along the lines of false readings without supplementation, im finding it hard to explain tbh.

Is b12 active/inactive inherently or is this something that the body modifies?

In other words, is the b12 we inject 100% active?

[Nackapan]

You are injecting b12. In your blood up to 80% will be inactive.

Your level will be high as in jecting every other day.

The advice seems to differ on how long you have to

wait when on frequent injections. I

cant see you gaining much info at the moment . Probably best to continue with your Injections for now. Shame it wasnt done after a longer break that you have had.

I've never had one. Wish it had been done prior to injections starting but a serum one was done. A intrinsic factor test was not done either my doctor did a parietal cell antybody test which was negative .

[fbirder]

When B12 enters your blood it will bind to one of two proteins, haptocorrin (HC) or transcobalamin (TC). It's nearly always the case the about 80% is HC-B12 and 20% TC-B12. Only TC-B12 is able to enter the cell, hence it being called 'Active' B12. Nobody seems totally sure of the point of having HC-B12.

When you have a B12 blood test it measures all of it, HC-B12 and TC-B12. Some people get all fashed about the fact that their measurement includes all that 'inactive' B12. And that somehow makes the test wrong. But the normal serum test and the 'active' test are just two different ways of counting the same thing.

It's like counting sheep. You can count heads, or you can count feet. Both will give you a good idea as to how many sheep you have (as long as you remember to divide the number of legs by four).

With B12 you can measure total B12 or Active B12, either will give you a good idea as to how much B12 you have in your blood.

The only real advantage to having the active test is that it is supposed to be more accurate and more precise than the standard serum test (which can give results that vary by up to 20% when testing the same sample twice).

I've never bothered with the active test as I know it will give the same result as the standard test - too high to measure.

[Hidden]

Fbirder gives a good description of the science behind the uptake of b12. I SI every 2 days. I have many symptoms. I do not test my b12. It is always over range. Eventually b12 will help or something else is the cause.

[Gumball77]

Funny to see this post after I had a GP phone appointment.

And I asked her about the same thing: is it worth having the b12 active test? She said she doesn't know. And she was shocked when i told her although I have monthly injections at the practice I have to SI after about 2 weeks because my symptoms return.

She was shocked as to why I need it so often! Martin, you have it every other day... what are your symptoms, please?

Thank you!

[fbirder in reply to Gumball77]

Point her to this - bmj.com/content/369/bmj.m13...

It is a letter to the BMJ from a retired doctor who needs injections once a month.

[JanD236 in reply to fbirder]

That’s really useful, thanks for posting.

There must be more medics with PA and I live in hope that some will need to inject more than once every 3 months and will be vocal about it!