Expert Q&A: Folic Acid Intake and Methotrexate 

Taking methotrexate can cause a folate deficiency. Here’s what you can do.  

Question: How much folic acid do I need to stay healthy?

Answer: The recommended dietary allowance (RDA) for adults is  micrograms/day. Most people get enough folic acid in their diets (legumes, leafy green vegetables, oranges, fish, fortified bread), but certain groups of people need more. For people taking methotrexate, mg or more of folic acid daily is recommended as a supplement. That’s because methotrexate blocks folate, a form of vitamin B that your cells need. Taking folic acid – a synthetic form of folate – can help protect against many potential side effects of methotrexate including GI side effects and liver enzyme elevation caused by folate depletion. Another group needing a folic acid supplement is pregnant women, because folate deficiency is associated with birth defects. If you have further concerns about how much folate you need, speak with your doctor.

Jasvinder Singh, MD


University of Alabama at Birmingham