Advice ref. B12 please

[Sotonowl]

Looking at getting some testing done by Blue Horizons and in the test I'm looking at it states B12 (Not active B12) anyone any idea what that actually means?

[Hidden]

Hi sorry I am new to all this too - I am looking at getting my Vit D, Vit B12 , folate and ferritin tested in the new year

Wishing you all the best with your tests

[Sotonowl in reply to Hidden]

And you mate.

[Hidden]

B12 is the total amount of b12 in your body, active b12 is the total amount available to your body to use. I believe up to 80% can be bound to proteins which means your body can’t access it.

[Sotonowl in reply to Hidden]

OK thanks for the reply. So the non active doesn't need to be tested and reported on as it's not available anyway?

[Hidden in reply to Sotonowl]

I believe doing the total amount of b12 is the first line of tests, and then if that’s low you can check the active b12. Are you in the uk? As I know st Thomas hospital do a b12 profile test which costs about £89, it checks active, total and mma. Might be of use to you

[Sotonowl in reply to Hidden]

I'm in Southampton. I'll be speaking to my GP on the 28th with a bit of luck. I haven't been diagnosed or tested, i'm just clutching at straws really, I haven't a clue whats wrong with me.

[Hidden in reply to Sotonowl]

Fingers crossed you get things sorted

[Gambit62]

Hidden The active B12 (or holo-T test looks at the amount of B12 in your body that is bound to a particular protein - TCII - which faclitates the transfer of B12 from your blood to cells where it is actually used. It isn't that being bound to other proteins means that your body can't use it because the other proteins TCI And TCiii are both proteins that enable your body to either transport B12 through the gut or to store it in the liver so it can be released and used as required.

In general 20-25% of the B12 in your blood will be bound to TCII so active B12 levels will tend to be 20-25% of total serum B12 levels.

There are other things - not related to absorption problems that can change these ratios.

A serum B12 or active B12 test tell you what is happening with absorption - it doesn't tell you what is happening with the other two main phases in using B12 - transferring it from blood to cells and actually using it in various processes in your cells - and there aren't direct tests for this - just other tests that can help clarify.

serum B12 is less expensive than active B12 because it is easier to measure all B12.

Neither test can be used as a definitive measure of whether you are B12 deficient or not as there is a lot of individual variation in how people respond to the levels of B12 in their blood - with the result that the logic of applying an average back to an individual doesn't really work - what is right for one person just isn't the same as what is right for another person.

On average serum B12 will fail to pick up 25% of people who are B12 deficient if it is used as a single measure. However, it will also pick up 5% who aren't deficient.

Whilst B12 isn't toxic - for some people raising B12 levels outside the normal range can cause problems as it can inhibit the process that allows B12 to pass from blood to cells, making it a lot less efficient and leading to cells not having enough B12 to run the processes they need to run. Please be careful about supplementing - especially if you aren't symptomatic of B12 deficiency ... and evaluating if you are symptomatic is going to be really difficult because of the overlap with thyroid problems.

[Hidden in reply to Gambit62]

Thanks gambit62, can I ask if they check mma, and it’s within range. Does that mean there is no problem with b12?

[Gambit62 in reply to Hidden]

honest answer is that most would say everything is okay if MMA is in range but there is at least one expert who thinks that MMA in range isn't conclusive.

Generally the expectation would be for a significant change in levels of MMA if there are problems with B12 levels in your cells. The build up of MMA is the result of a key process not running. It might be possible that a cell would prioritise one process over another but it would be extremely unusual for that process to be running at 100% if your cells were deficient in B12.

[Sotonowl]

Well there was an email from the Doctors waiting when I opened my inbox up this morning.

Had to ring the surgery and they want to take a blood test at 08-06 tomorrow morning.

In the e-consult I sent last Saturday (Think it was) I asked to be tested for Hypothyroidism, any one know what they will test for? Will they test the B12 as well?