Skip to Accessibility Tools Skip to Content Skip to Footer

Folic Acid and RA

Quick quiz: what do pregnancy and chemotherapy treatment have in common? If you guessed “folic acid supplements,” then you and I probably have some similar life experiences. I have been prescribed folic acid during four stretches of time in my life; once for each of my two pregnancies, and again during the two times rheumatologists put me on methotrexate.

What is folic acid?

Folic acid is a B vitamin that assists the body in making new cells.1 Folate occurs naturally in foods such as lentils, beans, asparagus, spinach, turnip greens, and broccoli.2 Folic acid is the synthetic version of folate that is available in supplement form. As folic acid has been shown to decrease neural birth defects such as spina bifida, it is not only recommended that pregnant women take the supplement, but it is mandated by the U.S. Food and Drug Administration that folic acid be added to enriched cereal products (cold cereals, pastas, breads, etc.).3

Dose recommendation for folic acid

Health practitioners recommend that women attempting to get pregnant take 400 mcg (0.4 mg) of folic acid daily.4 The dose recommended for individuals taking methotrexate is generally higher, as many people with RA are prescribed 1 mg of folic acid daily or 5 mg once a week. To understand why doctors recommend folic acid be taken while on methotrexate treatment, it’s important to understand how methotrexate works.

Why is methotrexate used for RA treatment?

Methotrexate is often called a chemotherapy drug, as it is used to treat cancer, although generally it is prescribed in much higher dosages for cancer than for rheumatoid arthritis. Methotrexate inhibits the metabolism of folic acid, which is needed for the production of certain immune system cells.

Less immune systems cells for a decrease in RA symptoms

Rheumatoid arthritis is an autoimmune condition, meaning that the immune system is confused and fights healthy joints, tissues, and organs rather than solely killing germs. Therefore, most medical treatments for RA target components of the immune system. In the case of methotrexate, it keeps certain immune system cells from being created, which in turn can cause a reduction in RA symptoms.

Folic acid, methotrexate, and RA

Unfortunately, methotrexate can also cause a wide variety of problematic side effects. As our bodies need folate for healthy cell growth, preventing the body from metabolizing folate often leads to folate deficiency. Symptoms of folate deficiency include gastrointestinal disorders, hair loss, tongue inflammation, and feeling sluggish.5 In addition, methotrexate can also impact liver function.6

Positive effects of methotrexate on RA symptoms do not disappear with folic acid

Taking a folic acid supplement can decrease or eliminate all of these side effects, and is therefore routinely prescribed for people taking methotrexate. 7 Interestingly, although methotrexate works by inhibiting the metabolism of folic acid, the positive benefits of methotrexate on rheumatoid arthritis symptoms do not disappear when taking a folic acid supplement.8 (However, folic acid supplements can impact the benefits of methotrexate treatment for cancer, and therefore may not be recommended for cancer patients.9)

Personally, I continued to experience side effects while taking methotrexate in spite of taking folic acid. However, many people in our online community have shared that it did indeed help with their side effects.

This article represents the opinions, thoughts, and experiences of the author; none of this content has been paid for by any advertiser. The team does not recommend or endorse any products or treatments discussed herein. Learn more about how we maintain editorial integrity here.



  • Ellenf
    3 years ago

    Does Leflunamide (Arava) have similar side effects and would adding folic acid supplements potentially help with my hair thinning and sluggishness?

  • Tamara Haag moderator author
    3 years ago

    Hi Ellen, thanks for reaching out with your questions! While Arava also has side effects, they can be different than Methotrexate’s side effects. I was unable to tolerate Methotrexate (even with folic acid) so my rheumatologist switched me to Arava, and I only had very mild side effects from it and now have no distinguishable side effects from it. Here is an article about Arava:

    Folic acid can mitigate some side effects of Methotrexate such as hair loss, but its benefits seem to vary from person to person. I recommend that you talk to your rheumatologist about your concerns and she what s/he thinks would be best for you.

    Please continue to reach out any time you have questions or concerns you want to share. Thanks for being part of our community!

  • Rosiegirl
    3 years ago

    I take a folic acid supplement with my Methotrexate. My hair has gotten thinner and I have lost almost all the hair on my arms. One leg has hardly no hair but the other still gets some I have to shave. Very odd!

  • Richard Faust moderator
    3 years ago

    Hi Rosie, Thanks for your question. Sorry to hear that you are having these issues with hair loss. One thing that you may want to ask your doctor about is other forms of folate. Folic acid is a synthetic compound form of a type of vitamin B. Folate is the water-soluble natural form of B9 that occurs naturally in various foods. Some people have trouble metabolizing folic acid. Your doctor could give you more information and look into whether you are one of these individuals and if so look at your treatment options. Note that this may not be the case at all and the hair loss simply a side-effect of the methotrexate that the folic acid cannot stop, but it can’t hurt to ask. Keep us posted on your progress. Best, Richard ( Team)

  • Tamara Haag moderator author
    3 years ago

    Hi Rosie, Thanks so much for reaching out and sharing! Unfortunately, a common side effect of methotrexate is hair loss, and the use of folic acid doesn’t eliminate this side effect for everyone. That is interesting that it is impacting more leg than the other; RA and its treatments constantly remind me how fascinating and strange the human body is! As with all side effects, if you have not already discussed this side effect with your rheumatologist, it would be advisable to do so. It is possible that your doctor may want to alter your dosage or try a different medication. Wishing you all the best, Tamara

  • Poll