Folic Acid dosage

Hi - the increase in folic so far to 4 tablets per week seems to be working because despite the raise in dose of Metoject I'm not feeling nearly as sick as I felt on the lower dose of MTX for the previous few weeks. I inject on Tuesday evenings and then take a folic tablet on Thursday,Friday,Saturday and Sunday as instructed.

I was trying to work out why different dosages are recommended for each of us and I found this on RA Warrior: "A small study (22 patients) showed that methotrexate is less effective at controlling psoriasis when folic acid is added. The folic acid dose in that study was 5 mg. daily, which is higher than the highest dose in the larger study previously mentioned. Conflicting results like these have prevented the formulation of a recognized guideline for all patients taking methotrexate for Rheumatoid Arthritis or other autoimmune disease. However, the consensus seems to be in favor folic acid supplementation since it is almost universal. Perhaps it will be determined that it is best to use as little folic acid as is necessary to counter methotrexate side effects."

Could this explain why, when I was taking 4 or 5 folic tabs last year while still on oral MTX, I was low on side effects but my ESR was still high and disease wasn't as well controlled? How does this work? I mean if we are advised to take more MTX but then have to be prescribed a higher folic acid intake to prevent nausea - and if the disruption of foliate absorption is what the MTX depends on in order to modify the disease - then surely this is a bit nuts? Why couldn't I just take a lower dose of injectable MTX with less folic and get the same results? I'm so baffled - can anyone explain?

13 Replies

  • II think you need to raise this with some one medically qualified in rhuematology. it is not a exact science and it is tailored to individual patients need and drug repsonses.

    The intenet can be a mine field and not always the best source of advice, maybe Nras could help they did a survey or rather poll on folic acid use/ prescribing.

  • Thanks. I asked my GP but he said he couldn't fathom it either and just to experiment with between 1 and 3 per week. I don't plan to experiment now will just stick to 4 per week as instructed but am just curious as ever - you know me! I will look for NRAS poll/ research thanks.

  • Well given that it seems that no-one really knows why MTX works for us, then it's not surprising that there are questions round folic acid too....? I guess that I view all of this a bit the same way that I do making crumpets. So you need to add baking powder to make the yeasty floury starter go all bubbly, but how much depends on the strength of the flour. And if you add it too early in the process, then your crumpet won't work either and you'll get a flat doughy mess. So if I think of us as individual crumpet mixes, then we're each going to need slightly different level of folic acid to replace the folate that the MTX has knocked out. But we have to add it in after the MTX, otherwise it could get in the way of MTX doing its thing? well that's my explanation anyway....Px

  • love that explanation!

  • I suspect, though not sure, that mtx works in other ways in addition to disrupting foliate absorption. If that is the case then the higher doses should be more effective even if Folic Acid intake is increased in line with the rise in mtx.

    But as my personal crumpet mix is a bit sticky right now with ESR on the rise I am tempted to ask about taking fewer Folic Acid tabs. Anyway I dropped this morning's one on the floor & lost it so that's one way of resolving the issue.

  • Well Ruby the puppy's quite foliated enough without me dropping any drugs on the floor to her waiting Kermit-like jaws! My husband came off a night shift having torgotten to throw away two loose paracetamols which were in his shirt pocket and the first we knew of this was when middle son stuck his finger into her mouth to find out what she was chewing. Then a panic ensued to find the other one - duly found and binned along with the first. I don't like to think what would have happened to her if she'd eaten it. I'm so happy not to be feeling more than a slight queasiness now that I don't actually care if the MTX is slightly compromised but the analogy of crumpets is quite nice actually - thanks Polly. Tilda xx

  • Hi Tilda

    We did do a poll on HU about this a while back, which is probably what Summer is referring to. Here's a link to it:

    Certainly from speaking to people on the helpline I would say that the use of folic acid varies greatly, and I think this is partly in catering to the individual, but probably also down to preference of the consultant. There seem to be no set guidelines on this, and the only constant is that people don't tend to take it on the same day as the MTX as it can make the MTX less effective.

    Kind regards


    (NRAS Helpline)

  • Thanks Victoria - I read through it and it was a very mixed bag wasn't it? Rather stupidly I have only just cottoned on to the idea that taking too much folic over a week may compromise the effectiveness of the MTX. I don't think it is simply a case of approaches varying according to the patient. It seems to me that opinion varies enormously according to each rheumatologist. Tilda

  • you're right I think - from my own experience & impressions about others here rheumies will sometimes suggest more or less Folic Acid but more usually they have their own ideas about optimum amount & tend not to think about adjusting it.

  • This article is a bit technical, but not too hard to get the general gist of and does give a good argument for taking folic acid with MTX (also compares it with folinic acid but thats another story and not generally an option here) - .

    I guess one of the really big variables is how much you are getting in your diet already. For someone like you, Tilda, who doesn't eat bread (that is often fortified with folic acid), you may not be getting anywhere near as much as others who do, though if you eat lots of fruit and veg that has it in naturally you may be getting more than someone who doesn't. So difficult to actually measure, which is why the easiest way of really figuring out what supplementary dose you need is really to start low, and just increase it little by little until you reach the dose that feels the best. You could then try going back a step and seeing if you still cope. In practical terms, if you want to tinker with the doses a little yourself, then easiest to get it slightly overprescribed, but get it in the smallest sized tablets so you can adjust the dose downwards yourself - no problems with taking less than prescribed, but you would have to check with a doctor if you wanted to take more.

  • Well before I had understood this much I was so paranoid about losing hair that I took about 5 tablets a week - then had a panic when I started feeling sick that folic might be compounding this and moved down to 2 or 3 a week (always avoiding MTX day). Then when the pharmacist told me that I was only to take one and was to review this with my GP I moved to one a week and that's when the sickness returned with a vengeance.

    Its slightly confusing for me because the Hydroxy quite often nauseates me a little too but I generally can tell which is which. So I am just going to stick to 4 a week again for the time being but I have at least learnt a lot on the way! Thanks Earthwitch.

  • now I am confused. I take 6 a week cos of hair thinning with the MTX. However it has made my blood glucose rise which I previously had under control. I am seeing rheumy in March so will question then.

  • Could it have been the MTX that made your blood glucose rise not the folic acid Sue? You will know more about it than me but I think my main query is to what extent the folic compromises the effectiveness of the MTX? Hope you get done answers in March for yourself.

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