Pernicious Anaemia Society
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Above high Folate / Vitamin 12 low

Does anyone know why standard blood tests come back >above high reference for Folate? I was very low 4 months ago but the last 2 tests have shown >above high reference 25, yet i have not been supplementing Folate. Levels of Serum B12 have been steadily dropping and the last test was 500 but i was symptomatic of low B12, iron and Vit D so suspect that it wasn't getting to the cells). I have been low in ferritin, deficient in Vit D (I have been supplementing Vit D3, Vit K2, Magnesium Glycinate, Liquid iron and Oral Spray Vit B12,).

If you supplement with B12, how can you tell when you have got levels to a reasonable level? Cannot find how to do this - only that it stays in the system for 4 months so B12 testing will not show accurate measures.

5 Replies


"last 2 tests have shown >above high reference 25, yet i have not been supplementing Folate"

Have you been eating a lot of folate rich food?

Link about folate test

"Levels of Serum B12 have been steadily dropping"

"but i was symptomatic of low B12"

Are you being treated with B12?

In UK, patients who are symptomatic for B12 deficiency are supposed to be treated even if B12 is within normal range.

Link about What to Do Next if B12 deficiency is suspected

Some B12 info

B12 Deficiency Symptoms

pernicious-anaemia-society.... (may need to be member)

Risk Factors for PA and B12 Deficiency


UK B12 documents

BSH Cobalamin and Folate Guidelines

Flowchart from BSH Cobalamin and Folate Guidelines

BMJ B12 article



B12 books I found useful

"What You Need to Know About Pernicious Anaemia and B12 Deficiency" by Martyn Hooper

Martyn Hooper is the chair of PAS (Pernicious Anaemia Society). Book is up to date with UK b12 guidelines.

"Living with Pernicious Anaemia and Vitamin B12 Deficiency" by Martyn Hooper

Has several case studies.

"Could it Be B12?: An Epidemic of Misdiagnoses" by Sally Pacholok and JJ. Stuart (USA authors)

Very comprehensive with lots of case studies.

PAS (Pernicious Anaemia Society)

Based in Wales, UK.


PAS tel no +44 (0)1656 769717 answerphone

PAS support groups in UK


UK B12 Blogs

Martyn Hooper's blog about PA

B12 Deficiency Info blog

Unhappy with Treatment (UK info)

Letters to GPs about B12 deficiency

CAB NHS Complaints

HDA patient care trust

UK charity that offers free second opinions on medical diagnoses and medical treatment.

Blood tests


Full Blood Count and Blood Film

Do you get copies of all your blood test results?

Access to Medical Records (England)

More b12 info in pinned posts on forum.

I am not medically trained.

1 like

Lots of interesting links, thank you. The hard part is getting a Dr to take it seriously. Most just think its hypochondria. It is far from that. I have adrenal issues also and wonder whether that has anything to do with it.


There is a phenomenon call "folate trapping" in which low cellular methyl B12 causes folate to become blocked in the one carbon folate cycle. The blockage can cause folate levels in the blood to rise despite normal folate intakes.

High folate levels combined with low B12 (I would include low cellular B12, i.e. functional B12 deficiency) are associated with cognitive decline.

As suggested in Sleepybunny's links, it would be worth considering active B12, MMA and homocysteine tests. Oral B12 does not work in everyone, particularly those with neurological symptoms. If you have strong neurological symptoms of B12 deficiency, and other causes have been ruled out, it may be worth considering a trial of B12 injections. Vitamin E deficiency can also cause neuropathies.

I am not medically trained but I have been B12 deficient for 13 years and my symptoms have all been neurological.


Thank you for the link to folate trapping - MMA and homocysteine tests have not been done.

September (G.P Bloods):

Serum B12 844ng/L

Folate Serum >25 Above high reference

Ferritin 51.00 (11.0 - 307)

Vit D 61nmol no range given

(Dr said everything fine)

December (Private Bloods):

Active B12 124.9 pmol/L (25.00 - 165.00)

Folate (Serum) 4.53ug (2.91 - 50.00)

Ferritin 42.2 ug/L (13.00 - 150)

25 OH Vit D *17.9 nmol/L (50.00 - 200.00) Deficient

(Started supplementing with Vit D3 after this)

February (G.P Bloods):

Serum B12 500ng/L

Plasma Folate >25 ug/L (3.8 - 25.0)

Ferritin 26.00 ug/L (11.00 - 307.00)

Vitamin D 162nmol/L

(Started supplementing Liquid Iron and Vit B12 Oral Spray after this) - I have adrenal issues and gut parasite issues and wonder if this is relevant.


Hi again,

(I have been supplementing .......Oral Spray Vit B12"

MMA, Homocysteine and Active b12 (holotranscobalamin) test results may be affected by recent B12 supplementation. See link about blood tests in above post.

"gut parasite issues"


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