B12 levels

[taka]

Random question... I've seen numbers such as 500 / 550 / 1000 (ng/L??) bandied about as levels you ideally need to be above while having treatment for PA. Does anyone by any chance have any links or scientific paper refs on things like this? Just curious!

[Gambit62 Administrator]

There are two sets of units used for measuring serum B12 - depending on where you are - pg/mol and ng/L - I can never remember which is which so the 500/550 is probably down to different units

500 is the cut off unit used in Japan to identify a B12 deficiency in the presence of symptoms of B12 deficiency

550pg/mol is the level recommended by B12 Awareness in the US as the correct cut off for defining the reference range for diagnosing B12 deficiency based on B12 serum results - but again this would be in the presence of symptoms.

Because nutritional absorption gets less efficient ... and so do other metabolic processes 1000pg/mol is the level B12 Awareness recommends as the correct cut of for evaluating elderly patients.

There are probably other sources for the numbers that people are aware of.

People vary a lot in how they respond to B12 so if you are being treated then the thing to do is to go by symptoms rather than any levels - my levels are permanently off the top of the scale because that is what I need in order to function after receiving B12 shots - all the ranges quoted are based on statistical averages and the important thing to remember is that people aren't statistical averages and its people that need to be treated.

[helvella in reply to Gambit62]

Gambit62,

I fear a typo near the start of your post.

The two sets of units are described reasonably, if briefly, in Wiki:

Serum vitamin B12 tests results are in pg/mL (picograms/milliliter) or pmol/L (picomoles/liter). The laboratory reference ranges for these units are similar, since the molecular weight of B12 is approximately 1000, the difference between mL and L. Thus: 550 pg/mL = 400 pmol/L.

en.wikipedia.org/wiki/Vitam...

[Gambit62 Administrator in reply to helvella]

thanks ng/L is the same as pg/mL = 1/1,000,000,000 g/L

Good to have the clarification on 550 v 400 so not quite got the 500/550 right

[helvella in reply to Gambit62]

In my earliest looking at B12 I was confused by the way that the numbers were often bandied around without reference to the units. I saw, specifically, Japanese papers using both units and realised that care really is required when near the limits.

[fbirder in reply to helvella]

Luckily the difference between pmol/L and ng/L are fairly small for B12 (smaller than the error in the assays). For most other things it makes a huge difference.

The medical world seem to be slowly moving over to molar values.

[helvella in reply to fbirder]

In my thyroid world, it seems to be molar everywhere except the USA and those who specifically follow them.

It would be interesting to see what effect use of molar values for dosing might have. For example, the thyroid hormone T4 changes weight by about 17% (or so) when converted to T3. Virtually all papers and medical sources ignore that completely.

[taka Administrator]

Thank-you for replying but I can't seem to find anything on the B12 awareness website about levels. Do you have a link by any chance?

[clivealive Forum Support]

On page 11 in the book "Could it be B12? – an epidemic of misdiagnoses” by Sally M. Pacholok R.N., B.S.N. & Jeffrey J. Stuart, D.O. under the heading "Types of tests for B12 Deficiency" talking about the Serum Vitamin B12 Test it says:-

"However, it appears that these markers demonstrate B12 deficiency primarily in patients whose serum B12 is in the "gray zone" (a serum B12 result between 200 pg/ml and 450 pg/ml). We believe that the "normal" B12 threshold needs to be raised from 200 pg/ml to at least 450 pg/ml because deficiencies begin to appear in the cerebral spinal fluid (CSF) below 550 pg/ml

At this time, we believe normal serum B12 levels should be greater than 550 pg/ml. For brain and nervous system health and prevention of disease in older adults, serum B12 levels should be maintained near or above 1,000 pg/ml."

I don't know if this helps taka

[Foggyme Administrator in reply to clivealive]

Oh well done clivealive . Just spent 20 minutes searching for this. I can stop now 🙃🙃😀

[taka Administrator]

Thank-you so much! I did wonder where these numbers came from. I must get round to reading some of the B12 books. Maybe over Christmas?

[Gcart]

Just add my experience . Serum B12 was. 411. So not too bad! Tested in July by blue horizon

Recommended on thyroid uk to supplement with B12 And B vits.

I had symptoms, numbness in both feet , pins and needles at night. Had mentioned to doc in the past. No comment was ever made about it. Had no idea what it was and just put up with it😕

RESULT after supplementing on that advice it's ALL GONE🙂🙂

Hope anyone else like me, not putting 2 and 2 together, can improve their health like me xx

By the way I must have been having that tested many times before because of routine hospital visits for another condition.!! Don't you think that could have been advised earlier to help me , Or am I sadly deluded 😈 I thought I was developing MS or the like.