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Pernicious Anaemia Society
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2003 article suggests B12 serum test may miss up to 1/2 of deficient patients

I found this 2003 article which makes a couple of interesting points:

1. The use of low serum B12 (< 200 pg/mL) as a sole means of diagnosis may miss up to half of the patients who have actual tissue B12 deficiency (they were looking at elderly patients)

2. If B12 is between 100 - 400 pg/mL, then MMA and homocysteine should be checked and a B12 deficiency is indicated if either of these are high (this logic is in the flowchart graphic, Figure 3)

They back these up with statistics from studies.

Article is here:


Title: Vitamin B12 Deficiency

Authors: ROBERT C. OH, CPT, MC, USA, U.S., Army Health Clinic, Darmstadt, Germany

DAVID L. BROWN, MAJ, MC, USA, Madigan Army Medical Center, Fort Lewis, Washington

Publication: Am Fam Physician. 2003 Mar 1;67(5):979-986.

3 Replies

Interesting, Tracy. That's 12 years old now, but I suspect lots of doctors would still argue with both points! And for reference on point 2, I asked my doc to have Homocysteine and MMA measured when my B12 was 384 and he said the NHS didn't do the tests. There's not a day goes by that I don't regret not insisting on having them done. Exceptionally valuable information to have - I wish I had it.


Yes I thought it was interesting particularly because it is an old article. Even back then there are those who realized there was a significant problem. And very sad that this has not changed even though it was recognized there is a problem with many people getting missed.

The medical community is very set in its ways, even if those ways are harming people. Darn near impossible to change things...


I know. It's a slow old dinosaur. More's the pity. Especially when you consider their ridiculously moribund ways literally kill people.


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