Low-ish B12: How important to be test... - Pernicious Anaemi...

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Low-ish B12: How important to be tested for PA?

aggleflaggle1045 profile image

Hello. This is my second post on this forum. Due to sudden, severe hair loss I'm seeing a Naturopath here in the U.S. She's an MD, but much more willing to treat and delve deeply into health issues that the mainstream docs I've seen. Here are some of my test results, which show I have Hashimoto's thyroid disease, low ferritin, and low-ish B12. I also have normal Magnesium and Zinc levels:

TSH: 3.27 uIU/mL (0.24 - 4.82) --my TSH has been around this number since at least 2015

Free T4: 0.72 ng/dL (0.59 - 1.61)

Free T3: 2.50 pg/mL (2.3 - 4.2)

Thyroid Perox AutoAb: 891 IU/mL (standard range: <35)

Vit D,25-Hydroxy Tot: 40 ng/ML (20-80) --I've been taking 2000iU VitD for a while now due to testing at 10 in 2016

Ferritin: 14 ng/mL (12 - 252)

RBC: 3.82 M/uL (3.90 - 5.40)

Hemoglobin: 12.1 g/dL (12.0 - 15.5)

Hematocrit: 35.7% (35.0 - 47.0)

MCV: 94 fL (80 - 100)

MCH: 31.7 pg (27.0 - 33.0)

MCHC: 33.9 g/dL (31.0 - 36.0)

RDW: Can't remember the number right now, but well within normal range.

Lymphocyte %: 22% (26.0 - 46.0)

Vitamin B12: 257 pg/mL (211 - 911) --tested at 284 in 2016

The doctor now has me taking all sorts of supplements, including iron, vitD, and magnesium and is starting me on a very low dose l-thyroxine to lower my TSH level. I'm taking another couple supplements to try to address the Hashimoto's.

She was also very concerned about my B12 level and is thinking it's a B12-specific absorption problem since my magnesium and zinc levels are within normal parameters.Today she recommended I start B12 injections, which I did.

My question has to do with this: When I asked her if I should be tested for PA, she said she didn't really think it was necessary because it wouldn't change the course of treatment. She thinks I'll need a few B12 injections to get my level above 500 and can then continue to do periodic injections or do a trial of sublingual B12 to see if that's sufficient. Her expectation is that I'll need lifetime B12 supplementation. So, how important, if at all, is it that I get tested for PA? Any advantages to doing so if I have it?


2 Replies
clivealive profile image
clivealiveForum Support

Hi aggleflaggle1045 the only "benefit" of having a definite P.A. diagnosis is that that guarantees B12 treatment for the rest of your life.

Sadly The Intrinsic Factor Antibodies (IFA) test is unreliable in that it gives false negatives in people with PA half the time. So a negative result doesn't mean that you don't have PA. However, a positive result is a sure-fire, 95% certain indicator of PA.

Treatment for PA and non-dietary vitamin B12 deficiency is virtually the same.

The symptoms of PA are the symptoms of the B12 deficiency that it causes. If the cause isn't dietary then it is an absorption problem so you need to find another way of replenishing B12 initially. Most absorption problems aren't treatable but a few are - notably h pylori infection - which would mean that once that has been dealt with you would be able to absorb B12 from your diet so wouldn't need maintenance shots for life.

People with autoimmune disorders, especially thyroid disorders such as Hashimoto’s thyroiditis and Grave’s disease are at an elevated risk of developing a B12 deficiency.

It is also important that your Folate level is monitored as this is essential to process the B12.

There is a complex interaction between folic acid, vitamin B12 and iron. A deficiency of one may be "masked" by excess of another so the three must always be in balance.

Symptoms of a folate deficiency can include:

symptoms related to anaemia

reduced sense of taste


numbness and tingling in the feet and hands

muscle weakness


Initially, replacing B12 will lead to a huge increase in the production of blood cells and platelets (which occurs in the bone marrow) and can lead to rapid depletion of folate and iron stores; this can then limit the expected recovery of Haemoglobin.

Both iron and folate may be needed so please have these levels checked by your doctor.

I am not a medically trained person but I've had Pernicious Anemia (a form of B12 deficiency) for more than 46 years.

I wish you well.

Gambit62 profile image

given that your two results 2016 and recent were pretty similar I'd personally be sceptical that you really do have a B12 absorption problem - should be seeing a significant drop in levels if you really do have an absorption problem.

Hashimotos does make PA more likely but I'd probably be looking more at thyroid being undertreated if your TSH is still that high and both T3 and T4 are coming out quite low in range.

The normal range is where most people are okay. There is no evidence that I am aware of that says everyone should have levels of 500+, or even that all thyroid patients should have levels of 500+. It seems to have come from the possibility of being B12 deficient and having neuro problems at these sort of levels but that is quite rare.

Symptoms do overlap with thyroid so makes things quite difficult in terms of diagnosing on symptoms - but I'd go back to the fact that historic figures imply that levels in the upper 200s are probably the levels approrpriate for you

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