Pernicious Anaemia Society
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How much folate or folic acid do you use daily alongside with B12 treatment?

That's it really - I'd like to hear from as many of you as possible.

I've started to take 1000 mcg methylfolate daily since starting on SI journey on this Monday.

However, I'm wondering if it's enough, as I've read lots of posts here of you guys supplementing 3000-4000 mcg per day.

On the other hand, I've read you shouldn't take too much folate or folic acid?

How much do you take? And how did you determine your 'right' dosage? How much B12 do you inject each week/month?

Many thanks! This forum is a life saver.

11 Replies

Hi SlimCat this is a difficult one to answer because we are all different

I'm not medically trained but I've had P.A. for 45 years and personally I have taken 1 – Folic Acid 400μg tablet for more years than I can remember and that is in addition to another 200μg contained in an "over 70s" multivitamin and that which is fortified into my daily breakfast cereals of All Bran and Grape Nuts - another 255μg so I'm well over the RDA for an adult male. However as I had two thirds of my stomach removed at the age of 17 in 1959 it can be said that I have "a bit of an absorption problem".

I've also taken 1 – Iron Ferrous Fumerate 210mg tablet every day, again for more years than I can remember.

I was started on cyanocobamalin 1000mcg B12 injections every four weeks back in 1972 and within the last few months have managed to get the frequency increased to every three weeks due to the return of neurological symptoms in the run up to my next injection.


Thank you Clivealive!

You're a complete legend. I've read so many of your very helpful posts before embarking on this treatment journey. Thanks a million.

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You make me sound like an old sock - that's a leg-end :D

Goodnight & God Bless.


Hilarious! :) Goodnight & God Bless to you too.


Right now I'm taking 2000mcg of methylfolate as I was finding taking less than 1000 mcg was not helpful for me, but taking 4000mcg was too much and caused side effects. You do have to be careful with folate/folic acid. You can take too much and the symptoms are not pleasant. Extreme irritability and agitation being one of them.

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This is an interesting discussion as I've been wondering the same, about how much folic to take. jbun (or anyone) please can you elaborate more on these symptoms of too much folate/folic acid? It would be good to know what to look out for. Thanks.


Hi Kirstenn555. Just to let you you ask 😉...posted a reply about folic acid and B12 safety...including information about potential side effects and cautions for both.



Thanks so much, Foggyme! I'll take a look - what a wonderful place this is! xx

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Slimcat. Just a few comments that might help (sorry, don't have time right now for a long post with lots of explanation):

About methyl folate: not many people need to take this (it's a different form of folic acid). Some people with a rare genetic variation should not take it at all: it can produce some quite nasty side effects: you're taking a very high dose - excessively high unless you've been diagnosed with folate deficiency and unless you know that you specifically need methyl folate (i.e. You have a rare gene variation that means it's the only folate that your body can metabolise). Many sites on the Internet 'push' methyl folate - most often the sites that are trying to sell it.

When methyl folate is required, guidelines suggest starting on a low dose (half a tablet - 200mcg) and increasing the dose slowly, if this is required. The dose of methyl folate you are taking could be a making you feel very ill.

(Note: The headaches your describe in a previous post could be due to over supplementation with methyl folate - and you may well have other side effects too).

About folic acid: it's not easy to get dosage of this right.

High doses (5mg daily) are only required if there is a proven folate deficency - and then only for a short period of time until the deficency is addressed.

The usual maintenance dose for folic acid is 400mcg daily (sometimes up to 800mcg daily, but only after trying the 400mcg first).

Some people do not required folic acid supplements at all - the only sure way to know how much to supplement with is by having your folate levels checked by your GP - and then supplement Ing accordingly, if supplements are required.

Taking high doses of folic acid can result in side-effects from over supplementation. Here's more information about that: Folate: Side Effects and Warnings)

Unless you have been specifically told by a medical professional that you need to take methyl folate, I suggest that you stop taking the methyl folate and swop to folic acid. Try the maintenance dose of 400mcg first - only take 5mg a day if you have a proven folic acid deficency - and get your folate levels checked by your GP (best way to assess what you really need).

If you are suffering side effects from the methyl folate (you can find these on the Internet) you may need to stop supplementing with any form of folate until your levels have dropped (again, only way to know is to get your GP to check your folate levels).

Also - I note in one of your previous post that you say you have started to SI with vitamin B12.

Not sure if you realise but by injection 2mls of a 1.5mg dose, you are injecting three times the recommended dose of B12 prescribed in the UK (the recommended dose is 1mg of B12 per injection - you appear to be taking 3mg per injection. Very few people need such high doses of vitamin B12 - you are essentially increasing the potential for side effects - and any excess B12 is usually excreted by the kidneys in the first twenty four hours following injection. (I note in your previous post you mention headaches - again, these could be due to the high doses of B12 you are taking (and/or the excessively high doses of methy folate - difficult to say which - may be a combination of both).

You may be better of injecting 1mg of B12 per injection and then adjusting the frequency of your injections to control your symptoms. Some people even find that injecting 500mcg per injection at more frequent intervals works better for them.

We're all different and everybody reacts differently to B12 treatment so it sometimes takes a little while to work out what dose and frequency works best for each individual.

Also - not sure if you are aware but there are cautions that you need to be aware of when injecting B12 if you have underlying health conditions. Here's more information about that: (The Mayo Clinic. Vitamin B12: Side Effects and Warnings: Pre-existing Health Conditions)

About frequent high doses of B12: injecting B12 freqently can lower potassium levels to dangerous levels. However, potassium supplements should never be taken unless under direct medical supervision (potassium levels are finely balanced and too much can be as bad as too little - either could have a dangerous effect on how the heart works). Ideally, if you are injecting B12 on a very frequent basis, your GP should monitor your potassium levels. This is especially important if you have any underlying cardiac conditions.

As you do not have a confirmed diagnosis of vitamin B12 deficency (and we all know how problematic this can be) please keep in mind that the symptoms of B12 deficency have many cross-over symptoms that can also be present in other medical conditions.

If the symptoms that you suspect are due to B12 deficiency are not relieved by the B12 injections, you should see your GP and rule out the possibility that your symptoms could have other under lying medical causes.

In addition, if you have neurological symptoms and these persist, you should ask to be referred to a neurologist to rule out other potential underlying conditions.

Likewise, referral to a gastrologist may be required if you have unresolved gastric symptoms.

Post again if you need any further help...lots of lovely folk here to pop along to support you.



Foggyme, thank you so much for your fabulous reply. I really appreciate you taking the time to reply.

Many thanks for warning re methylfolate. You made some very good points. I'm now going to switch to Folic Acid -- provided that I need to supplement at all as my daily multivitamin already contains 400 mcg Folic Acid...?

I'm just worried about not getting enough Folic Acid to work with the B12. Really trying to put lots of leafy greens in at least one meal a day.

The reason I decided to self inject 3mg every other day is that I read a few amazing studies - I'm pretty sure I first found the links here initially - where in one of them they supplemented 10mg a week for 2 weeks (and then 2 weeks placebo) and got really good results; and in the other they supplemented even larger doses and kept giving as much as the individual could take with their symptoms still improving -- if I remember right, up to 9mg per injection on some individuals.

As I have a history of being so scared of needles that I've been known to cry and nearly faint at the doctors several times (sometimes just at the sight of a needle in a film too) I reasoned to myself that it might be better to take larger doses and not so often, if you see what I mean. Thank God my headache is currently not present but I will surely keep an eye on it and do less Hydroxo and daily injections if there's a link. Thanks :)

Also, in reference to the studies I mentioned above (which you might probably know quite well) I felt hopeful at how they very quickly got results with patients after just 1-2 weeks of these huge loading doses. I've been so desperate with the fatigue in recent months - actually, I've struggled with fatigue on and off for 10 years, more on than off, but gave up with GPs back in 2010 when years of going to the doctors crying about how the symptoms are holding me back from living my life did not produce any results (except being treated for iron deficiency anaemia, for which I've again been treated for months, without noticeable results in symptoms though my bloods are now improving and in the okay range again).

So, when I found out about B12 when browsing the net on holiday a month ago - when I thought I could recover my energies in the sun, but in fact was so tired that spent most of the holiday sleeping which was rather depressing - I felt like, this treatment could actually help. So, fingers crossed. Just now I had my third injection and felt like crying again. It's a psychological thing - thank God the injection does not actually hurt at all, taking the plaster off hurts much more!

Thank you so much for replying. This forum is brilliant. I'm pleased that so many people have found help from B12. It remains to see whether I'm one of them but I remain hopeful :)

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p.s. Thanks also re warning re potassium levels. I'm eating at least 4-5 bananas a day (they're my favourite snack anyway) and also drinking the gross coconut water even though I think it's vile! :) I hope that would be enough? But you're right it's very important to bear the potassium levels in mind.

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