Folic acid is a synthetic form offolate, a natural form of vitamin B9 derived from food.
Folate deficiency is a common side effect of methotrexate use.
Taking folic acid with methotrexate reduces the risk of this by replacing lost folate in the blood.
Verywell / JR Bee
This article explains what folate deficiency is and how methotrexate contributes to it.
It also describes how folic acid is taken while you are on methotrexate therapy.
Oral methotrexate is available in 2.5 milligram (mg) tablets.
Methotrexate injection is given under the skin (subcutaneously).
It comes as 25 mg per 1 milliliter.
In children with juvenile rheumatoid arthritis, the dose is based on the child’s weight.
Despite these beneficial effects, methotrexate can deplete folate faster than it can be replenished with food.
To avoid folate deficiency, folic acid may be prescribed alongside methotrexate to supplement your natural stores of folate.
What Is Folate Deficiency?
Folate is also needed for a process known asmitosis, in which cells divide to form two identical cells.
Folate is awater-soluble vitamin, meaning that it is not stored in fat cells.
Moreover, folic acid can reduce the risk of methotrexate withdrawal if ever treatment is stopped.
It is available as a tablet and an oral liquid.
Does folic acid reduce the effectiveness of methotrexate?
Daily use of folic acid does not appear to affect methotrexate efficacy.
You may also be told to take folic acid 24 hours after receiving a dose of methotrexate.
There is no standard dose of folic acid when taken alongside methotrexate.
People taking methotrexate should get their folic acid by prescription rather than buying it over the counter.
Folic acid is generally well tolerated and usually causes few side effects.
High doses may cause nausea, stomach upset, bloating, gas, and diarrhea in some people.
By doing so, methotrexate can cause folate deficiency, leading to anemia and other potentially serious complications.
Frequently Asked Questions
Methotrexate works by blocking the action of folate, also known as vitamin B9.
This can lead to folate deficiency and complications such as anemia.
Folic acid is often given as a single 5-milligram (mg) dose for people on methotrexate.
In such cases, the folic acid should be taken the dayafterthe methotrexate dose.
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Arthritis Foundation.Methotrexate: Managing Side Effects.
U.S. National Library of Medicine: MedlinePlus.Folate deficiency.
Office of Dietary Supplements.Folate: fact sheet for health professionals.
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National Library of Medicine.Methotrexate boxed warning.
