THE VITAMIN B12 AND FOLATE PATHOLOGY INVESTIGATION
THE INVESTIGATION OF ERRORS IN PATHOLOGY TESTS
FOR VITAMIN B12 AND FOLATE DEFICIENCY
BY MEANS OF MEDICAL EXPERIMENTS
THE SERUM VITAMIN B12 INVESTIGATION
THE SERUM B12 EXPERIMENT - A
Summary
Method
Observations
Results - Notes
Results - Assay Quality
Results - Analyte Utility
Conclusions
Diagnositic Utility

Serum Vitamin B12

The only lab to measure my serum B12 levels, Sullivan Nicolaides Pathology (SNP), failed to indicate the onset of vitamin B12 deficiency because they quote a "normal" range that is far too low. Using a minimum "normal" of 130 pmol/L, instead of the 295 pmol/L recommended by experts, could cause results to be seriously misinterpreted. This could lead to a failure to diagnose cases of vitamin B12 deficiency, potentially resulting in irreversible neurological damage.

Having regard to the results of my investigation, set out in this web site, in my opinion Sullivan Nicolaides Pathology serum B12 quoted "normal" range cannot be relied on for the diagnosis or monitoring of vitamin B12 deficiency.

Serum Vitamin B12 Compared to Serum Methylmalonic Acid

Serum vitamin B12 is a much less sensitive indicator of vitamin B12 deficiency than methylmalonic acid.

Although serum vitaminB12 was sensitive to the intake of high dose oral B12, it failed to detect the onset of B12 deficiency after the oral B12 was ceased. This insensitivity is illustrated by the very slow decline in serum B12 level, while the methylmalonic acid increased rapidly above the cut-off.

Serum vitamin B12 may be useful to confirm that high-dose oral B12 is absorbed, but cannot be used to detect the onset of cellular vitamin B12 deficiency. A "normal" serum vitamin B12 result is deceptive because it cannot reliably reflect the true metabolic state of the patient.

Serum Vitamin B12 Compared to Serum Total Homocysteine

The comparison of serum vitamin B12 with total homocysteine is not as clear as the comparison with methylmalonic acid. This is because of doubts about the results from Sullivan Nicolaides Pathology and the quality of samples supplied to Westmead.

Although there were significant differences between them, results from both laboratories showed a significant increase in total homocysteine in the latter part of the experiment.

Serum vitamin B12 failed to detect the onset of cellular deficiency, while total homocysteine did detect a change in metabolic state.

 

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