Folic Acid Deficiency: What Happens When You Don’t Get Enough Folic Acid (B9)?

Oct 19, 2021 Folic AcidWomen's Health 5 MIN

Folic Acid Deficiency: What Happens When You Don’t Get Enough Folic Acid (B9)?

Quick Health Scoop

  • Men and women—especially women of reproductive age—need folate (also called folic acid) in their diet
  • A folic acid deficiency may cause a variety of symptoms
  • A folate deficiency may be caused by a poor diet, alcoholism, and/or certain diseases or conditions that prevent the body from absorbing and processing folate
  • The best way to increase folic acid intake is through a folate-rich diet and supplements containing folic acid

Folate (and its synthetic form known as folic acid) provides a variety of health benefits, such as helping healthy cells divide, producing nucleic acids such as DNA and RNA, and making red blood cells. This important B vitamin can be found naturally in many foods such as leafy green vegetables, legumes (lentils, beans,peas), and fruit, however,it’s also used in supplements and in fortified foods like breakfast cereal. But what happens when you have low folate levels?

Learn More: Folic Acid Health Benefits

First, let’s start with who needs folic acid. Everyone—including men, women, and children—needs this important nutrient. According to the National Health and Nutrition Examination Survey (NHANES) data from 2003-2006 the prevalence of folic acid deficiency in the United States has decreased from 16% to 0.5% since the dietary folic acid fortification program started in the late 1990s.1  Because adequate folate as part of a healthy diet helps reduce the risk of neural tube defects in developing babies, the CDC recommends that all women of reproductive age take a daily dose of 400 mcg of folic acid in addition to eating folate-rich food.2

While folate deficiency cases in generally healthy people are rare—they do occur. The prevalence of folate deficiency was >20% in many countries with lower income economies but was typically <5% in countries with higher income economies.3 Folic acid helps your body make red blood cells. A lack of folic acid in the blood can cause anemia, also referred to as megaloblastic anemia. Excessive consumption of alcohol, poor diet, and an inability to absorb nutrients may lead to low folic acid levels along with other nutrient deficiencies.2 Amongst pregnant women, a folic acid deficiency can be serious. 

Let’s dig into the causes of folic acid deficiency as well as what symptoms to look for with a folic acid deficiency 

Learn More: Folate vs Folic Acid: What’s the Difference?

What Causes Folic Acid Deficiency in Adults?

The body uses folate, a water-soluble B vitamin, as needed and the rest is excreted in urine. Is it good to take folic acid every day? Yes! Because your body doesn’t store this nutrient, you need to regularly consume folate (also known as vitamin B9) to replenish your body’s supply. Your blood levels will decrease after just a few weeks of eating a diet low in folate.4

What blocks folic acid absorption? Poor diet, alcoholism, and certain conditions may prevent the body from absorbing and processing folate, which may lead to folate deficiency. For example, alcohol can be a culprit, as it may hinder folate absorption and increases the amount of folate the body excretes.5

Who is most at risk for folic acid deficiency? Certain people can develop a folate deficiency, including those who: 4

  • Don’t eat enough folate-rich foods, such as legumes (beans, peas, lentils), leafy green vegetables, fruit, fortified cereals, and meats (including liver)
  • Consume alcohol
  • Have difficulties with processing folate
  • Take medication that may may prevent the body from absorbing and processing folate
  • Are pregnant and those who are wanting to become pregnant (because the growing baby needs more folic acid and the mother absorbs it more slowly)

What Are the Symptoms of Folic Acid Deficiency?

Low folate can lead to deficiency, with symptoms that include weakness, fatigue, difficulty concentrating, irritability, headache, heart palpitations, and shortness of breath.2 

If you’re pregnant and don’t get enough folate, your baby can be born with neural tube defects—severe deformities that affect the spine and spinal cord (spina bifida) or brain (anencephaly) and may cause death.6

Other signs of folic acid deficiency include: 2 

  • smooth, tender tongue
  • color changes in skin, hair, or fingernails
  • decreased appetite
  • gastrointestinal issues (diarrhea) 
  • increased blood concentrations of homocysteine 

Learn More: What Prenatal Vitamins Do You Need?

How Do You Improve Folic Acid Deficiency?

You can increase your folic acid by improving your diet and focusing on eating a well-balanced diet of folate-rich foods, taking folic acid supplements, while addressing any underlying health issues under the care of a healthcare professional.5

How long does it take for folic acid to correct a folic acid deficiency? If you’ve got a poor diet, you’ll need to make some lifestyle changes to include more foods high in folic acid. Taking folic acid supplements, such as folic acid tablets, for at least two to three months may also help support your nutrition needs. If you drink alcohol, you should limit the alcohol you consume.

How much folic acid do you need per day? Your daily folate intake depends on your age, lifestyle, and gender. However, generally healthy adults should take 400 mcg per day, while pregnant teens and women should take 600 mcg per day.2,7

Can you have too much folate? While you can't get too much folate from foods that naturally contain this nutrient, you should aim for no more than 1,000 mcg of folic acid a day.7

The Bottom Line

Both men and women need folate (a.k.a. vitamin B9) in their diets, and if you don’t get enough, it can lead to deficiency.  You can get folate naturally through healthy foods, (like beans, leafy greens, and fruit) but you can also get it in its synthetic form (folic acid) in some fortified foods and supplements. And if you’re a woman of reproductive age, take folic acid, either as an individual supplement, a women’s multivitamin, or a prenatal or postnatal vitamin

Continue to check back on the Nature Made blog for the latest science-backed articles to help you take ownership of your health.

Learn More About Women’s Health:

† These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.


  1. FoDiaz, K et al. Prevalence of Folic Acid Deficiency and Cost Effectiveness of Folic Acid Testing: A Single Center Experience. Blood (2018) 132 (Supplement 1): 4878.
  2. National Institutes of Health. “Folate.” March 22, 2021. Accessed on: August 12, 2021.
  3. Rogers, Lisa M et al. “Global folate status in women of reproductive age: a systematic review with emphasis on methodological issues.” Annals of the New York Academy of Sciences vol. 1431,1 (2018): 35-57. doi:10.1111/nyas.13963
  4. Medline Plus. “Folate Deficiency.” August 5, 2021. Accessed on: August 27, 2021.
  5. Healthline. “Folate Deficiency.” August 3, 2020. Accessed on: August 27, 2021.
  6. OASH Office on Women’s Health. “Folic Acid.” April 1, 2019. Accessed on: August 12, 2021.
  7. Oregon State University Linus Pauling Institute. “Folate.” December 2014. Accessed on: August 12, 2021.


Lisa Beach

NatureMade Contributor

Lisa Beach is a seasoned journalist whose work has been published in The New York Times, Good Housekeeping, Eating Well, Parents, AARP’s Disrupt Aging, Optimum Wellness, and dozens more. She also writes for a variety of health/wellness-focused brands. Check out her writer’s website at

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Lynn M. Laboranti, RD

Science and Health Educator

Lynn is a Registered Dietitian (R.D.) and is a member of the Medical and Scientific Communications team at Pharmavite. She has over 20 years of experience in integrative and functional nutrition and has given lectures to health professionals and consumers on nutrition, dietary supplements and related health issues. Lynn frequently conducts employee trainings on various nutrition topics in addition to educating retail partners on vitamins, minerals and supplements. Lynn has previous clinical dietitian expertise in both acute and long-term care, as well as nutrition counseling for weight management, diabetes, and sports nutrition. Lynn earned a bachelor’s of science in Nutrition with a minor in Kinesiology/Exercise Science from The Pennsylvania State University. She earned a M.S. degree in Human Nutrition from Marywood University in Scranton, Pennsylvania. Lynn is an active member of the Academy of Nutrition and Dietetics, Sports Cardiovascular and Wellness Nutritionists, Dietitians in Functional Medicine, and holds a certification in Integrative and Functional Nutrition through the Academy of Nutrition and Dietetics.

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