Pernicious Anaemia Society
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Can it come back

I was prescribed folate tablets for 4 months roughly 3 years ago. I had blood test 15 months ago which the doctor said checked for low B12 levels and it was ok. The last year has been uttterly awful both physically and mentally and I feel exhausted and fatigued all the time, have got depressed as well. Could the levels have dropped in this time? My doctor says not and doesn't think it is worth testing again.

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Hi Sheba12345 can you remember why you were prescribed folic acid 3 years ago? Was it because you had low B12 at that time?

Can you be more specific about your symptoms and tell us more about your lifestyle, surgeries, medications, illnesses, diet etc.

I'm not medically trained but there are others on here who will be able to give you good advice - don't be afraid to ask.


Try to get hold of the B12 results from the blood test a few years ago. Serum B12 is not a good guide to what is happening at the cell level which is what counts and it isn't uncommon for someone to have clear symptoms of B12 deficiency whist in the normal range (which is only a statisical average anyway).

It may be that other blood tests haven't shown any abnormalities in your red blood cells and unfortunately GPs tend to be incorrectly fixated on what is happening with red blood cells - but 30% of people who are B12 deficient present with other symptoms long before any affect on blood cells is detected.

Whilst diet is a possible cause of a B12 deficiency (it is only found in animal products) it is rare and so it is much more likely to be an absorption problem. The liver stores quite high levels of B12 but these are released to be reabsorbed by the same mechanism that absorbs B12 from your food so it is like having a leaky bucket if you have an absorption problem and your levels can deplete quite quickly - so it is quite possible that your levels may have fallen.

Having said that there are other things that cause symptoms that are very similar to B12 deficiency and sometimes more than one thing is going on at the same time.

You can find a checklist of symptoms of B12 deficiency here


If the surgery you go to has more than one GP then it might be an idea to try seeing another one - explain the situation and ask if they will retest, and do some other investigations to look at what is making you feel so tired.


"which the doctor said checked for low B12 levels and it was ok."

I learnt from experience to always get copies of my blood test results with reference ranges. In the past I was told on more than one occasion that my tests were all normal/okay and found that there were abnormal (out of range) results when I got copies. In relation to B12, I look at B12, folate, ferritin and full blood count (FBC).

Have you looked at lists of b12 deficiency symptoms?


B12 books

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

"Could it be b12" by Sally Pacholok and JJ. Stuart

B12 websites


B12 documents/articles

There's a lot of useful info about b12 in the pinned posts on this forum.

If you're UK based it might be helpful to google "BCSH Cobalamin and Folate guidelines".

I found page 8 and page 29 particularly useful.

A recent BMJ article on B12

Other links

Important info in Management section in above link.

I am not a medic just a patient who has struggled to get a diagnosis.

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