Pernicious Anaemia Society
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Low Folate/Memory problems

Hi, My hubby seen Dr recently due to sudden and quite severe memory problems and unusual bruising/bleeding under skin.She ordered FBC bloods. He got a phone message to say he has low folate and is to take 5mg a day for six months.Am I correct in saying low folate can mask a b12 problem? I am going with him on next appointment and will ask for a copy of his lab results.I have PA myself and know how foggy my brain can be but nowhere as bad as he is.

12 Replies

Yes folate supplements can mask a B12D. Get the B12 sorted first, even if "normal" but <400pg/ml.

Folic acid then supports the B12.


Taking folate can mask the anaemia/macrocytosis that can be the result of a B12 deficiency. (not the deficiency itself) I would advise to get B12 tested before taking folate (I believe it also states that in the folate leaflet, not take when B12def) If B12 is low get treatment of course and then add the folate. If B12 is lownormal and dr won't treat, then test further (MMA/homocysteine/PA) and then add B12. If he has neurologic symptoms this is essential. And with memory problems he has, so I would do that. Also 5mg for 6 months is IMHO very long and in general not necessary (unless on certain medication that lower folate) So don't take folate until you know B12 is fine as it can exacerbate neuro symptoms.


Thank you for the very helpful info. Confirms exactly what I was thinking.I wont wait till his appointment at GP I will contact surgery asap to find out what they have tested for.


Where would you get a MMA/homocysteine/PA test please?


As PA Administrator says it is high folate that can mask the effects of B12 - specifically the development of macrocytosis. As folate is needed to process and use B12 the symptoms of low folate are very similar to low B12 ... and as macrocytosis isn't always one of the first symptoms of B12 deficiency it would be very easy to miss a B12 deficiency if you are only looking for macrocytosis.

Get hold of a copy of the blood results that were done - they may have included B12 anyway but it may not have come out as being outside the normal range. If it serum B12 hasn't been done then try to get MMA and homocysteine as follow up - though homocysteine isn't generally available on the NHS - use the materials on the importance of assessing B12 deficiency on symptoms rather than absolute results from the pinned posts to try to get through to the GP.

And don't start the treatment for folate deficiency until you are sure that there isn't a B12 deficiency going on as well.


Hello. Back with an update! I phoned hospital to chase up a date for husbands scan turns out GP had not requested one?? Phoned GP she invited us to come in this evening. She was insistent that B12 will have been done with FBC I sat forward and asked to see the result.She then popped out for a moment,came back and said she was arranging for further blood tests incl B12(YES!!!) also apologized for forgetting to book scan.I queried 6months of folic she said yes four months is the norm but six wont do any harm.Also found out he is vitD deficient.I am definitely withholding the folic until we get B12 results.Thinking this is going to be a long long journey.

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Is it safe to take b12 supplements


The EFSA (European Food Standards Agency) has not set an upper limit for supplementing B12 because it could not find any evidence of harmful effects at high dose.

hydroxocobalamin is the treatment of choice for cyanide poisoning because of its lack of side-effects and particularly any dangerous side effects.

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See "Management" section in next link

Has you husband had a ferritin (stored iron) test? Macrocytosis (enlarged red blood cells) can be masked in someone with low folate and/or low B12 if they also have low iron levels because low iron can lead to microcytosis(small red blood cells).

Have you got copies of all his blood results. i learnt that what I was told was normal face to face or over the phone was not always normal when i got copies. Some surgeries have online access to test results or patients can make a formal written request for copies ,likely to be a charge per copy.

Have you got copies of previous blood results over last few years?

I have found it helpful to monitor results over several years. Some people on this forum get their complete set of medical records, expensive but can be interesting. Have heard of people who found out that they had previously been diagnosed with PA but were not told at the time. Fairly easy to get complete medical records from GP surgeries, formal written request but more difficult to get medical records from hospitals.

I found it very helpful to read the following document,

"BCSH Cobalamin and Folate Guidelines"

Page 29 is a diagnosis flowchart that shows the process a medic should follow with someone they suspect has a B12 deficiency. Page 8 gives details of Uk B12 treatment for those with and without neuro symptoms. Folate treatment is also discussed.My understanding is that patients who are symptomatic for B12 deficiency in the UK are supposed to be treated even if b12 levels are normal range.

See 5th point in following link

Lots of people have to be very assertive to get medics to consider the possibility of b12 deficiency. It has taken me close to 20 years......

B12 symptoms lists

I gave a copy of PAS list to my Gps with all my symptoms ticked.


B12 books

"What You Need to Know About Pernicious Anaemia and Vitamin B12 Deficiency" by Martyn Hooper, this book is up to date with UK guidelines.

Could It Be b12 by Sally Pacholok and JJ. Stuart, very comprehensive book

Other links


I am not a medic jsut someone who has struggled to get a diagnosis.


Hi Sleepy bunny, Turns out husbands cancer had come back with a vengeance GP was barking up the wrong tree! I arranged ct scan myself!



I hope your husband now gets the help and support he needs from the medical profession.

Having PA can lead to an increased risk of stomach cancer.

If you browse the various communities on HU, there may be one that can offer support.


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