Pernicious Anaemia Society

High B12 whit high MMA whit no supplementation


I am male, 38 years old, from Brazil.

I am not supplementing b12 when I did these blood tests. I tested for serum b12 and serum MMA and get this results:

B12: 997 pg/ml Ref: 211 – 911

Folic Acid: 21,3 ng/ml Ref: > 5,38

Methyl Malonic Acid: 0,62 umol/L Ref: 0,08 – 0,56

So, I have high b12 whit high MMA without supplementing b12.

So, whit these results, I starting taking methylb12, 5.000 mcg, but stopped because I fell more tired whit this. So take 1.000 mcg of hydroxocobalamin instead and fell a little better, but not symptoms free.

My symptoms are:

- Low body temperature

- Pain, heaviness on legs

- Liquid sperm (I am sterile now)

- Fatigue

Did other blood test, now taking hydroxob12, and my serum b12 goes to > 2.000 pg/ml. Don’t tested MMA this time.

Can I don’t have a b12 deficiency but other disease that increase MMA?

Thank you.

7 Replies

Please go and see your doctor/a doctor. There are a number of conditions which can cause high B12 and high MMA without supplementation - and getting them diagnosed early if they are nasties is important.

Raised MMA is a potential indicator for liver and kidney problems.

B12 will promote the growth of of cancerous cells as well as non-cancerous cells so could lead to larger tumours if the underlying problem is cancer. I would hold off on further supplementation with B12 until you have ruled out the other potential problems.

This article was about using high B12 as a way of getting early diagnosis of some liver and kidney problems.


The problem is my liver and kidney are ok. Liver enzymes, creatinine, urea, everything is fine.

What is the best type of doctor to see it?


the article posted as an edit to my response includes a few possibilities for raised B12 in absence of supplementation - guess they would suggest either a haematologist or an oncologist but I am not a medic so really don't feel qualified to advise beyond speaking to your doctor - may be share the article posted as basis for discussion - along with your blood results.


ok, Thank you very much


I would re-test MMA. If it has decreased significantly then most likely your B12 was false high. That would be step 1. Your B12 was high, but not too high before, but MMA was clearly much too high. If kidney-disease has been ruled out, then there are only a few options left, one they would have foudn (hypovolemia) and the other is bacterial overgrowth in the intestine (which can be tested) So start by doing MMA again and if that is still high then go see a specialist, any internal medicine would be fine as long as they know what MMA is.


just to ad that my homocysteine is low, below 6.


Homocysteine is less specific for a B12def than MMA as it is highly influenced by folate intake. It's very possible to have B12def with normal homocysteine. Just have the MMA re-tested to see what's going on, and go from there.


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