I have never heard of "active b12 test" Is it the same thing as an MMA? Does it matter if b12 treatment has already been started? Iam fine as long as I take methly b12, by jarrow everyday. If I miss a few days my feet and hands start to vibrate and I get twitches in my lower legs. But supposedly, by my MMA, I have built up enought stores. What I don't seem to be able to comprehend is: if your body stores 5-6 years worth of b12 and it takes a long time to become depleated how is it possible to build it back up so fast? And if the stores are built up why would I have symptoms after only missing a few days?

variation from person to person in everything biological.

There are genetic polymorphisms, there is damage to the liver, damage from
infection, damage from autoimmune events, etc.

Everything you read here and at OBT ( on Vit D ) is based on just the most
recent knowledge. It cannot be perfect...cannot pertain to everyone.

You will see more stories now (like this week) that taking a simple multivit...
causes CANCER--- and from HARVARD no less. This is a response to the
desire by the drug companies to control the supplement movement. And also reflects the bias the medical community holds against anything that threatens its existence as a high price commodity (which millions here can no longer afford).

So if you can control your symptoms for 9 cents a day.... DO IT.
(in the face of no destructive data...which is the situation for B12-- our own government has a website suggesting B12 for all people over 50. Do you think that will change too? Perhaps).

Thanks for the reply msrd. I will not stop taking methly b12, ever. I was posting this thread in response to a previous thread by Paul. He said to lable it why get tested first.

Hello cat265,

I will reply to each question in order. I have also replied to your PM.

For information about the holotranscobalamin test, I suggest that you read my reference BH6. Here is a direct link to the document:

Active-B12 (holotranscobalamin)

There are direct links to many more references on holotranscobalamin on the references page of my web site; there is a whole section for this test.

No, the active B12 test measures the component of total serum B12 that is available to the cells for metabolism. Only about 10 to 30% of total serum B12 is attached to the transport protein, transcobalamin to become the holotranscobalamin. The proportion of holotranscobalamin falls significantly as body stores deplete, so the active B12 test should indicate a deficiency earlier than the total serum B12. I can see one serious potential weakness of this test; it still only measures the B12 available to cells, not how well they utilize it.

The MMA test measures the amount of toxic chemical left over from an incomplete reaction, due to B12 deficiency. It therefore is an indicator of actual cellular deficiency, not just what is available to the cells.

I am currently comparing active B12 and MMA, as well as total B12 and homocysteine, as my deficiency worsens. I hope to soon be able to publish my results on my web site.

Yes, it does matter, if you are trying to use active B12 for diagnosis. Once you have started treatment, your active B12 level will reflect your current body stores, even if you stop for a few weeks. Just as for MMA, or homocysteine or serum B12, you cannot return to your pre-treatment condition just by ceasing treatment.

If you want to use active B12 to assess effectiveness of your treatment, then you can do that by ceasing treatment for one or two weeks before testing. The half-life of holotranscobalamin is a few hours (the experts give a range of minutes to hours), so one week should be sufficient.

The figure of 5-6 years is what some experts say is total body storage; others say it is 20 to 30 years. These figures are for a healthy person who has built up a full store of B12 then suddenly stops taking any, for example becoming a vegan. If there is onset of a severe disease process that interrupts recycling of B12, the stores can deplete much more quickly; typically one to three years.

You should build up your stores much faster than they can deplete, even if you have the most severe case of deficiency, by using oral supplements. This is possible because of a process called passive diffusion. You can absorb about 1% of any B12 dose by passive diffusion, so a dose of 1000 µg will yield about 10 µg effective B12, even if there is no normal absorption. It will therefore take 200 to 300 such doses to fill your body stores, which normally hold 2 to 3 mg. There are some conditions where a person cannot absorb any oral dose, even by passive diffusion, but this would show up in any serum B12 test following treatment.

This is explained well by Kuzminski, in my reference BN1. Here is a direct link to the document:

Effective treatment of Cobalamin Deficiency With Oral Cobalamin, Kaminski et al, Blood, Vol 92, No 4, 1998: pp 1191-1198

You have asked the question that has been puzzling me for some time, and that I am currently trying to answer with my testing. I do not have a very clear answer for you.

Many other patients have described, on these forums, very rapid re-appearance of symptoms between treatments, but usually when using injected B12.

I cannot compare this to my own personal experience because I am unable to easily correlate my many symptoms, which vary with time anyway, with treatment. I therefore rely entirely on biochemical tests to determine the effectiveness of my treatment.

Iff (and I mean if and only if) the experts are right, you should not have any recurrence of symptoms after stopping your treatment for a few weeks. This is because, even in the most severe case of deficiency, your body stores should last for one to three years.

This leads to a few unanswered questions:

• Is the body store really filled?
• If so, is it actually available for metabolism?
• Does the body store have to be full to overflowing before B12 is available to cells?

I hope that my current research will give us some answers.

To get some idea of just how difficult this problem is, even for the experts, I suggest that you read the report by Solomon, my reference BK9:

Disorders of cobalamin (Vitamin B12) metabolism: Emerging concepts in pathophysiology, diagnosis and treatment, L. Solomon, Blood Reviews, Volume 21, Issue 3, Pages 113-130

You have asked a very good question. I am sorry that I cannot answer your question better than this, at this time.

Paul

*******************************

But please keep in mind, that most doctors' eyes would glaze over and
turn off if you requested this cutting edge testing.

I am not trying to discount his data, but doctors in this country are resistant,
poorly informed and also form value judgements against the patient, in the form of mean diagnoses in the chart... hypochondriac, malingerer etc and that goes
on YOUR record for other doctors and insurance to read.

So while we need good testing... I don't think it is available to most people reading here in US (and perhaps in other countries).

Here in the US it is just becoming more common to do MMA instead of B12 serum levels. MMA is a precise tool to show if B12 is working at all, since the test measures the only precise effect of B12 on one enzyme system. You could have
tons of free B12 floating around in the blood doing NOTHING... for all anyone knows.

Also binding proteins are dependent on protein intake, and a whole slew of other enzyme functions having to do with blood proteins, before it can be carried around. Aging and other variables can really negatively affect these proteins.

The subject is just huge...many things working or not working in concert properly. Medicine is just not equipped for this yet.

Hello mrsd,

As you said:

I agree with what you say but I think that you might have misunderstood the intention of my post. I was not promoting the active B12 test; I was responding to a specific question about this new assay. The question arose from my response to Jackie, in her thread "B12 deficiency- still having problems!". In my post, I said:

As I have not yet completed my own investigation of the active B12 test, I cannot yet confirm that it is as effective as the kit supplier claims it to be.

The active B12 (holotranscobalamin) test is intended to ultimately replace the total serum B12 assay. Unlike the MMA test, this new active B12 test uses an automated immunoassay, so is inexpensive. The cost here, in Australia, is between $25 and $45 per sample, so should be similar in USA. It is covered by Medicare in Australia, if serum B12 is not tested at the same time.

I have been able to locate two labs in USA who list the active B12 test in their online catalogue. There are likely to be many more actually doing the test but have not yet listed it. There are at least four labs in Australia offering the test now, so there are certain to be many more in USA where Abbott Laboratories, the kit supplier, is located.

Here are the links to the labs:

Specialty Laboratories

American Clinical Services

You said:
Yes, they are the same here as well. I was labelled as a malingerer and hypochondriac for 40 years, until my ventricular tachycardia was finally discovered in 2004, at the age of 51 years. The full story is on the About Me page of my web site; I suggest that you read it if you want to know what is driving me.

I was similarly labelled when I discovered my B12 deficiency in 2005. This is why I am on a mission to get the message across about vitamin B12 deficiency.

Fortunately, I now have an excellent GP who has a strong interest in nutritional medicine, and who very supportive, as is my psychiatrist. I also now have the cooperation of three labs, which do the testing directly for me.

So, regardless of the level of resistance, I intend to force change in the way that B12 deficiency is diagnosed.

Paul