Hi Birgitta,
the newer literatur reveals that there have been made mistakes in diagnosing
Vitamin B12 deficiency.
The "normal" blood test for vitamin b12, is the cheapest,but not able to identify the active component of Vit B12, so that it does not detect if this lacks. A HoloTC-Test should be done first in the screening of risk groups, which shows early when the vitb12 stores in organs and body-cells become empty. Also the lower reverence levels for the "normal test" are too low. With a minimum of 200 ng/l/nanograms/liter, = 148 pmol/l /picomol/liter)) you would be in the range.
Prof. Herrmann (and not only he but authors even 20 years ago) recommends a minimum of 400pmol/l (= 542ng/l)in a review from 2008 He is in my knowledge - most specialized professor for laboratory medicine, Prof.Dr. Wolfgang Herrmann. He also has written the B12 - chapter in the standard book "Labor and Diagnose", - even more scientifical. In our Viennese Library there are about 20 exemplaries from it for the students:
Causes and early diagnosis of vitamin B12 deficiency.
http://www.ncbi.nlm.nih.gov/pubmed/19623286
free fulltext, with algorithm for laboratory diagnosis
There is also existing a book on amazon "Could it be B12?" which has 2011 appeared in the 2nd edition with many citations and advices also for medical practicioners. For me it has become already a "must", because it gives an overview. Reports and reviews on pubmed are more specialized.
After having searched in this forum for B12 i am not convinced in some cases that the diagnosis has been done in the way described in both abovementioned publications.
In my case it was only done with the "normal" test on diagnosis in 9/2007, my values were 468pmol/l= 634,14ng/l . On January 2,2008, after three AML-chemothrapies, i organized the counts from a private laboratory: Only 107 pmol/l =144,98 ng/l This was too low. I showed to the doctors and got 2 shots of VitB1. Never again B12 was monitored.Actually my counts are about 256 pmol = 346,88 ng/l . Enough for the normal mesurement but too low for the new one. Also i have got a lot of neurological problems actually and want to try the Vit B12 supplementation.
Also I phoned yesterday to a University Professor from the Institute for Medical and Chemical Laboratory Diagnostics, sent him the article (and he was interested studying the problem).
Probably many patients are not diagnosed in time for vitb12 deficiency. Hopefully, that also in our city the special tests will be re-invented (there was no demand from the doctors so they stopped doing HoloTC some years ago... In the american book "could it be b12" it has been mentioned also in the 1st edition of 2005, also an UMMA test, which seems to be unknown here in Vienna..
This is my status of information
I think, with more than 1000 .... in your blood in most cases you will not suffer from Vit B12 deficiency.
Kind regards,
Margarete