What happens if you take folic acid twice a day?

In this brief article, we will discuss, “What happens if you take folic acid twice a day?”. We will talk about the potential health concerns of taking folic acid twice a day and the best possible way to take folic acid to make the most out of it. 

What happens if you take folic acid twice a day?

Taking folic acid twice a day or taking a higher-than-recommended dose may cause side effects like rash, itching, nausea, gas, bloating, stomach pain, etc (1). However, oral folic acid is not considered toxic and taking it accidentally twice will most likely not subject you to disturbing side effects (2). 

Folic acid is a type of vitamin B that is essential for various bodily functions. Being water-soluble, any excess amount of folic acid is usually removed from the body through urine – which is why overdoses are not considered that harmful (3).

However, it is important to note that people may react differently to higher doses of folic acid. Some individuals might experience side effects like nausea, bloating, gas, or even skin rashes. If you suspect any adverse reactions, it’s crucial to consult your healthcare provider.

What are the dosage recommendations for folic acid?

General dosage recommendations for folic acid are: (4,2)

ConditionAdult dosesAdministration
Megaloblastic anemia1 mgOral, IM, SC, IV, once a day. May continue until symptoms improve.
Folic acid deficiency400 to 800 mcgOral, IM, SC, IV, once a day.
Pregnant or Lactating women/women of childbearing age400 to 800 mcgOral, IM, SC, IV, once a day.
People using Methotrexate (Option 1)5 mg once a weekTaken 24 hours after Methotrexate dose
People using Methotrexate (Option 2)1 mg daily Take orally daily, except on the day of Methotrexate dose.

*IM: Intramuscular, SC: Subcutaneous, IV: Intravenous.

What are the health risks associated with persistent folic acid overdosing?

Persistent folic acid overdosing can lead to several health risks, especially when consistently taking higher-than-recommended doses. While folic acid is water-soluble and generally considered safe in appropriate amounts, excessive intake can have negative consequences (5).

Long-term folic acid overdosing may cause gastrointestinal discomfort, including bloating, gas, and nausea. These symptoms can be bothersome and affect daily life (1,5).

Another concern is the masking of vitamin B12 deficiency (6). High folic acid levels may hide the symptoms of vitamin B12 deficiency, which is crucial for nerve function and red blood cell production. If left untreated, vitamin B12 deficiency can lead to nerve damage and anaemia.

In some cases, excessively high folic acid intake may result in unmetabolized folic acid circulating in the bloodstream. This could be linked to potential health risks, though more research is needed to fully understand the implications.

How to ensure the proper use of folic acid?

Ensuring the proper use of folic acid is essential for maintaining good health, as this vital vitamin plays a crucial role in various bodily functions. 

To use folic acid properly, it’s important to follow general guidelines that apply to everyone. Take the recommended dose at the same time each day to ensure a consistent intake of the vitamin. Avoid taking more than the prescribed dosage, as excessive folic acid intake may lead to potential health risks

If you happen to miss a dose, take it as soon as you remember, but do not double up on doses to make up for the missed one. If you have any concerns or questions about folic acid supplementation, consult your healthcare provider.

If you’re pregnant, taking the recommended dose is especially crucial to prevent birth defects in your baby’s brain and spine (4). For certain health conditions like anaemia, your doctor might prescribe higher doses, but follow their instructions to avoid taking too much.

Not taking folic acid properly or missing doses can lead to deficiency-related issues like anaemia, fatigue, and weakness. It’s especially important during pregnancy to avoid complications (2). 

Using folic acid the right way supports healthy cell division, DNA, and RNA formation, which is essential for your overall well-being. So, be sure to follow your healthcare provider’s advice and take folic acid as directed to stay healthy and strong.


In this brief article, we have discussed the potential side effects of taking folic acid twice, the proper dosage recommendation, and the proper use of folic acid supplements.

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National Library of Medicine. Folic Acid: MedlinePlus Drug Information [Internet]. Bethesda (MD): U.S. National Library of Medicine. Available from: https://medlineplus.gov/druginfo/meds/a682591.html


National Health Service. How and when to take folic acid. [Internet]. London: National Health Service (NHS). Available from: https://www.nhs.uk/medicines/folic-acid/how-and-when-to-take-folic-acid/


Butterworth CE Jr, Tamura T. Folic acid safety and toxicity: a brief review. Am J Clin Nutr. 1989 Aug;50(2):353-8. doi: 10.1093/ajcn/50.2.353. PMID: 2667316. https://pubmed.ncbi.nlm.nih.gov/2667316/


Centers for Disease Control and Prevention, CDC. Folic Acid [Internet]. Available from: https://www.cdc.gov/ncbddd/folicacid/about.html


Merrell BJ, McMurry JP. Folic Acid. 2022 Dec 21. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan–. PMID: 32119374. https://www.ncbi.nlm.nih.gov/books/NBK554487


Mills JL, Molloy AM, Reynolds EH. Do the benefits of folic acid fortification outweigh the risk of masking vitamin B12 deficiency? BMJ. 2018 Mar 1;360:k724. doi: 10.1136/bmj.k724. Erratum in: BMJ. 2018 Mar 21;360:k1334. PMID: 29496696; PMCID: PMC6889897. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6889897/