Potential Risks and Complications Associated with Excessive Folic Acid Intake

4 Potential Side Effects of Too Much Folic Acid


Folic acid, also known as folate, is a B vitamin that is essential for the proper functioning of the body. It plays a crucial role in the synthesis of DNA and RNA, the production of red blood cells, and the prevention of neural tube defects during pregnancy. While folic acid is important for overall health, it is possible to consume too much of it, which can lead to various side effects.

1. Digestive Issues

One of the potential side effects of consuming too much folic acid is digestive problems. Excessive intake of folic acid can cause symptoms such as nausea, abdominal bloating, and diarrhea. These symptoms are more likely to occur when high doses of folic acid are taken in supplement form. If you experience any digestive issues after taking folic acid supplements, it is advisable to consult with a healthcare professional.

2. Masking Vitamin B12 Deficiency

Another possible side effect of excessive folic acid intake is masking a vitamin B12 deficiency. Folic acid can correct the megaloblastic anemia caused by a vitamin B12 deficiency without addressing the underlying problem. This can lead to the progression of neurological damage associated with vitamin B12 deficiency, as folic acid does not treat the neurological complications of B12 deficiency. It is important to ensure adequate intake of vitamin B12 along with folic acid.

3. Increased Risk of Cancer

3. Increased Risk of Cancer

While folic acid is needed for proper cell division and growth, excessive intake of folic acid may increase the risk of certain cancers. Studies have suggested that high levels of folic acid may promote the growth of preexisting cancer cells or accelerate the progression of certain types of cancer, such as colorectal cancer. However, more research is needed to fully understand the relationship between folic acid and cancer development.

4. Interaction with Medications

4. Interaction with Medications

Folic acid supplements can interact with certain medications, leading to potential side effects. For example, folic acid can interfere with the effectiveness of certain antiepileptic drugs, potentially reducing their ability to control seizures. It can also interact with certain medications used for the treatment of rheumatoid arthritis and methotrexate, increasing the risk of adverse effects. If you are taking any medications, it is important to talk to your healthcare provider before starting folic acid supplements.


While folic acid is essential for optimal health, it is important to avoid excessive intake. Consuming too much folic acid can lead to digestive issues, mask vitamin B12 deficiency, increase the risk of certain cancers, and interact with medications. It is always best to consult with a healthcare professional before starting any new supplements or significantly increasing your folic acid intake.

Dietary folate equivalents

Dietary folate equivalents (DFE) is a unit of measurement used to compare the amount of folic acid consumed from fortified foods and supplements with the naturally occurring folate found in food. Folic acid is the synthetic form of folate, which is converted into the active form of the vitamin in the body.

While both folic acid and naturally occurring folate are important for the body, they are not metabolized in the same way. To account for this difference, a conversion factor called the DFE is used to calculate the total folate intake. The DFE takes into consideration the different absorption rates and bioavailability of folic acid and folate.

For example, when 1 mcg of folic acid is consumed from fortified foods or supplements, it is equivalent to 1.7 mcg of DFE. On the other hand, when 1 mcg of naturally occurring folate is consumed from food, it is equivalent to 1 mcg of DFE.

The DFE is important to consider when determining the total intake of folic acid, as excessive consumption can lead to potential side effects. It is recommended to consume no more than 1,000 mcg of folic acid per day from fortified foods and supplements, unless specifically directed by a healthcare professional.

By understanding the concept of DFE, individuals can make informed decisions about their folic acid intake and reduce the risk of experiencing the potential side effects associated with excessive consumption.

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