Folate (folic acid): benefits, side effects, supplements

Can you imagine trying to build a piece of furniture without the right instructions? The task would be daunting. Much like instructions can help us build things we need in our homes, instructions can also help the cells in our bodies to function, reproduce, and make proteins. DNA—or deoxyribonucleic acid—supplies our cells with such instructions (NIH, 2020). And, in order for our bodies to make DNA, we need folate.

Folate, also called vitamin B9, is an essential nutrient that you need to consume regularly so that your body has the resources it needs to form red blood cells, create new proteins, and, as we said above, lend a hand in producing DNA (Mercadante, 2021; Merrell, 2021). 

While everyone needs some folate, some people need greater amounts than others. Let’s take a deeper look at folate, how it impacts your body, and when you might need to supplement with synthetic folate (folic acid). 

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Folate, also called vitamin B9, is a water-soluble vitamin. What this means is that your body can't store folate for very long. You must get a certain amount of folate from food sources or supplements (Lystad, 2021). While the bacteria in your colon make some folate, it is unclear how much this amount contributes to someone having enough folate (NIH, 2021). 

Folate vs. folic acid 

People sometimes use folate and folic acid interchangeably, but they aren’t exactly the same thing. There are a few different types of folate that have slightly different molecular structures (Shulpekova, 2021). 

Folate is the broad umbrella term that refers to all forms of the vitamin. Folic acid is a synthetic form of folate that we add to foods or consume in most dietary supplements (NIH, 2021). Folate is the form of the vitamin that is naturally found in food sources (Khan, 2021). 

Everyone needs folate so their cells can function correctly. Without folate, your body could not make DNA or RNA. DNA carries the instructions your cells need to reproduce, develop, and function (NIH, 2020). Your body also needs folate so your red blood cells can mature correctly (this helps prevent anemia) (Merrell, 2021).

Getting enough folate has several benefits. Some research suggests that getting enough folate might decrease your risk of getting certain types of cancer (Pieroth, 2018). But overall, the relationship between the risk for cancer and taking folic acid supplements is unclear, and health experts need to do more research in this area (NIH, 2021). 

Another area of interest is the relationship between folate intake and cardiovascular disease. For example, taking folic acid supplements might help decrease some people’s risk for stroke (Qin, 2016).

While there is still much research to be done on folate’s benefits on other aspects of health, the fact that this B-vitamin plays a role in the creation of DNA and RNA is reason enough to make sure you’re getting enough of it.

Women of childbearing age and pregnant women are at particular risk for folate deficiency. These women should get a higher amount of folate to help prevent neural tube defects in any developing children (NIH, 2021).

The neural tube is the portion of the unborn child that will eventually develop into the brain and spinal cord. If the neural tube fails to develop properly, a child can have disorders like spina bifida, which can severely impair a child’s nervous system and overall ability to function (Singh, 2021). Not getting enough folate during pregnancy may also increase the risk of preterm birth and fetal growth problems.

We still don't fully understand how folate impacts other areas of health. Some research suggests that not getting enough folate during pregnancy is linked to children having autism. But at this point, there is no proof that folate deficiency in pregnancy causes autism (NIH, 2021).

Your body does not store folate for very long, so you need to consume folate regularly to ensure your body has enough of it (Merrell, 2021). 

The general recommendation is that people over 19 years old should consume about 400 micrograms (mcg) of folate daily. Women who are pregnant should take about 600 mcg of folate daily. Women who are breastfeeding should take in about 500 mcg of folate daily (NIH, 2021).

Folate occurs naturally in several foods. Common food sources of folate include fruits, green leafy vegetables, and liver (Khan, 2021). Eggs, beef, chicken, and milk also have folate (NIH, 2021).

Other foods have folic acid added to them. Adding folic acid to foods is a common practice in several countries. In the United States, grain products like flour, pasta, cereals, and bread often have added folic acid (NIH, 2021). Remember, you can always check the nutrition label to see if a food has added folic acid.

Folic acid supplements

Folic acid supplements are also available, and pregnant women will often take a daily prenatal vitamin that has folic acid in it. Healthcare providers typically recommend that women who want to get pregnant should start taking a prenatal vitamin about a month before attempting conception and up through at least 12 weeks gestation (Mousa, 2019).

As with any vitamin or nutrient, you can get too much or too little of it. However, some people are more at risk for folate imbalances than others. For example, people who drink large amounts of alcohol are at risk for folate deficiency because alcohol interferes with folate absorption. People with malabsorption disorders or a genetic disorder called MTHFR polymorphism are also at risk for a deficiency (NIH, 2021).

Too little folate

When you get too little of the vitamin, you are at risk for megaloblastic anemia—a type of anemia that occurs when the body cannot make normal red blood cells (Hariz, 2021). Its symptoms include fatigue, irritability, headache, shortness of breath, and heart palpitations (NIH, 2021). Folate deficiency can also cause an overall low number of red blood cells, white blood cells, platelets in the body, and inflammation in the mouth and tongue. People with a deficiency might also experience mental and nerve symptoms like fatigue, depression, irritability, and insomnia (Khan, 2021).

Too much folate

Since the body doesn't store folate for very long, the risk for folate toxicity is very low, and there is no upper-level intake of folate naturally present in foods. However, you can theoretically get too much folic acid in supplements or fortified foods and beverages, and people should not consume more than 1,000 mcg of folic acid from these sources (NIH, 2021). 

The bottom line is that everyone needs folate and most people get enough through the foods they eat or from foods fortified with folic acid. Sometimes, supplements are necessary for groups that need to take in large amounts of folate, such as pregnant women. 

Seek medical advice about your folic acid intake needs if you are pregnant or planning on becoming pregnant. If you are concerned that you aren't getting enough folate or are in an at-risk category, talk with your healthcare provider.

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Current version

November 30, 2021

Written by

Jessica Norris

Fact checked by

Felix Gussone, MD

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About the medical reviewer

Felix Gussone, MD, Ro

Felix Gussone is a physician, health journalist and a Manager, Medical Content & Education at Ro.