Skip to content

Folate Deficiency: 5 Signs You're Not Getting Enough Vitamin B9

From fatigue to mouth sores, these are the signs to look out for.

B vitamins serve a range of important functions in the body: They help you form new blood cells and maintain cellular health, promote metabolism (the conversion of food into energy), and contribute to your heart and brain health. In particular, folate—also known as vitamin B9—works with vitamin B12 to make red blood cells and to utilize iron in the body. Having too little folate, known as a vitamin B9 deficiency or a folate deficiency, can affect your red blood cells and cause a range of health problems.

Wondering how to spot a problem—and what to do about it? Here's everything you need to know about folate deficiencies, including the five symptoms to look out for.

RELATED: 7 Low Magnesium Symptoms to Watch Out For, According to Doctors.

Why Do Our Bodies Need Folate?

Caring female doctor use phonendoscope examine senior patient heart rate at consultation in hospital. Woman nurse or GP use stethoscope listen to woman's heartbeat in clinic.

Your body needs folate to perform a range of basic functions, many involving healthy cell formation and growth.

"Folate is essential for DNA synthesis, cell division, and forming red blood cells," says Raj Dasgupta, MD, medical reviewer for NCOA and an ABIM quadruple board-certified physician specializing in internal medicine, pulmonology, critical care, and sleep medicine. "It's especially crucial during pregnancy for preventing birth defects and supporting overall growth."

Michelle Routhenstein, MS, RD, a preventive cardiology dietitian and registered dietitian nutritionist at Entirely Nourished, adds that it's also critical to maintaining good heart health.

"Folate helps to support the nitric oxide pathway, crucial for relaxing blood vessels and ensuring optimal blood flow, contributing to overall cardiovascular health," she explains. "Folate plays another important role in heart health by helping to regulate homocysteine levels in the blood, which, if elevated, can increase blood clots and heart disease risk."

RELATED: 7 Protein Deficiency Symptoms, According to Doctors.

What Does It Mean to Have a Folate Deficiency?

Are you getting enough vitamin B nine (folic acid)?

A folate deficiency occurs when the body doesn't have enough folate to meet its needs. Most teens and adults need 400 mcg of dietary folate equivalents (DFE) daily.

However, according to the National Institutes of Health (NIH), pregnant people require 600 mcg DFE, and people who are breastfeeding need 500 mcg DFE.

As one study published in the Journal of the American Dietetic Association explains, dietary folate equivalents ("DFEs"), account for the difference between the absorption of naturally occurring food folate and synthetic folic acid, which is its more bioavailable form.

"The quantity of dietary folate equivalents occurring naturally in food equals the micrograms of folate as reported, and the dietary folate equivalents provided by fortified foods equal the micrograms of food folate plus 1.7 times the micrograms of added folic acid," the study authors write. "Currently, the use of dietary folate equivalents is recommended for planning and evaluating the adequacy of people's folate intake."

RELATED: 7 Calcium Deficiency Symptoms, According to Doctors.

Who Is Most Prone to Low Folate Levels?

pregnant woman sitting and consulting doctor
Syda Productions / Shutterstock

There are several groups of people who may be at a disproportionate risk of folate deficiency. In particular, Routhenstein says anyone whose diet includes "an inadequate intake of folate, such as those following a strict carnivore diet, limited amounts of fruits, vegetables, legumes, soy, and whole grains, may be at risk of a folate deficiency."

Pregnant and breastfeeding women, who have higher folate requirements than the rest of the population, are also at an increased risk of folate deficiency—especially if they don't adjust their diets or supplements to meet that higher need.

Individuals with certain medical conditions that affect folate absorption or metabolism may also be at an increased risk of folate deficiency, adds Routhenstein: "This includes celiac disease, inflammatory bowel disease, and certain liver disorders."

How Is a Folate Deficiency Diagnosed?

Lab worker preparing test blood for detection of antibodies and infections
Parilov / Shutterstock

The best way to find out your folate status is to request a blood test known as serum folate testing from your doctor. Your doctor may also wish to order a complete blood count (CBC) test, which measures your number of red blood cells and can also detect certain blood cancers, anemia, infections, inflammation, and other conditions.

"Serum folate testing usually is an adequate measurement of folate levels, but if your physician suspects a folate deficiency despite normal serum folate and ruled-out B12 deficiency, red blood cell folate levels may be further evaluated," says Routhenstein.

RELATED: 9 Supplements That Can Damage Your Stomach, Doctors Say.

Folic Acid Deficiency Symptoms

There are several symptoms associated with folic acid deficiency, though it's important to note that many of these are non-specific and can resemble symptoms of other illnesses.

1. Fatigue

Fatigued senior mature man eyestrain can't see
fizkes / Shutterstock

Chris Mohr, PhD, RD, a fitness and nutrition advisor at Fortune Recommends Health, says people with folate deficiencies may experience fatigue and weakness if they develop folate deficiency anemia. This is usually due to reduced red blood cell production and can also occur in the event of abnormally low hemoglobin levels in the red blood cells.

2. Pale skin

Older woman massaging nose bridge.

Mohr says pale skin can also be a sign of folate deficiency or folate deficiency anemia because there aren't enough red cells in circulation. Though having pale skin is not typically suggestive of an illness, changing from your regular skin tone to an unusually pale hue can suggest a problem.

3. Shortness of breath

Man holding his chest having a hard time breathing

Some people with folate deficiency will experience shortness of breath due to insufficient oxygen transport, Mohr notes. This can sometimes also be accompanied by rapid breathing, the UK's National Health Services (NHS) adds.

4. Irritability or mood changes

Women angry looking at her phone
fizkes / Shutterstock

Some people with folate deficiencies will also notice that they are more irritable than usual, experiencing mood swings and behavioral changes.

"Folate deficiency has been associated with the presence of depression, may hinder response to antidepressants, and may contribute to relapse of depression," notes a 2009 article in the Journal of Clinical Psychology. "Low levels of folate, a B vitamin, have also been associated with poor cognitive function, which is common among patients with depression."

5. Mouth sores

Man is having mouth pain, toothache

Mohr says mouth sores and related oral swelling or pain can also be signs of a folate deficiency.

"Recurrent aphthous stomatitis (RAS), commonly referred to as canker sores, is a very common and painful oral mucosal disease. Although the etiology of RAS is not well understood, a number of factors may play a role, including nutritional deficiencies," says a 2010 study in the Journal of Oral Pathology and Medicine.

"Our results demonstrate that patients with recurrent aphthous stomatitis are more likely to have lower dietary intakes of vitamin B12 and folate than a control group… These findings suggest that consuming sufficient amounts of these vitamins may be a useful strategy to reduce the number and/or duration of RAS episodes," the study authors wrote.

RELATED: 5 Signs You're Not Getting Enough Vitamin B12, Doctors Say.

What Conditions Are Related to Folic Acid Deficiency?

iron deficiency blood test

The primary condition that's related to folic acid deficiency is folate deficiency anemia, or in medical terms, megaloblastic anemia. This occurs when a body that lacks adequate vitamin B12 or vitamin B9 begins producing abnormally large blood cells, and fewer of them.

However, that's not the only health condition associated with folate deficiency. "Conditions related to folic acid deficiency can also include cardiovascular disease and certain types of cancer," notes Routhenstein.

She adds that when pregnant women have folate deficiencies, this can increase the risk of neural tube defects in newborns. As Johns Hopkins Medicine explains, neural tube defects are a category of neurological disorders that can be linked to malformations of the spinal cord, including spina bifida, anencephaly, meningocele, myelomeningocele, and tethered spinal cord syndrome.

RELATED: 12 Supplements You Should Never Take Together, Medical Experts Say.

Folate Deficiency Causes

Inadequate diet


The primary cause behind folate deficiency is having a poor diet from not eating enough folate-rich foods, says Dasgupta. Foods that are rich in folate or folic acid include citrus fruits, dark leafy green vegetables, legumes, asparagus, eggs, peas, nuts, berries, and more.


A glass of whiskey on wooden bar with holiday lights behind it
SOMKID THONGDEE / Shutterstock

Malabsorption is another underlying cause of folate deficiency. This can be triggered by a medical condition, certain medications, excessive alcohol intake, or pregnancy and breastfeeding.

"Malabsorption issues from conditions like celiac disease or Crohn's can hinder folate absorption. Excessive alcohol can interfere with folate absorption and metabolism," Dasgupta says.

Certain medications

Young woman taking medicine, vitamin with water at home. Modern lifestyle and healthcare concept.

Some drugs can affect your folate levels, so it's important to keep a comprehensive list of medications and supplements you take, and share those with your doctor.

"Certain medications, like anticonvulsants or anti-seizure medications (e.g., phenytoin, carbamazepine), methotrexate, sulfasalazine, and specific antibiotics (e.g., trimethoprim), may decrease folate absorption or utilization, potentially leading to an increased risk of a folate deficiency," says Routhenstein.

RELATED: 5 Supplements That Can Damage Your Kidneys, Doctors Say.

How Can You Treat a Folate Deficiency?

Food rich in folic acid or vitamin B9. Natural food sources of folic acid: avocado, cauliflower, broccoli, eggs, tomato, spinach, beans, nuts, parsley

If you have a known folate deficiency, your doctor will most likely recommend dietary changes, as well as folate supplementation.

"Establishing a comprehensive nutritional plan with a registered dietitian while supplementing folate is crucial to prevent future deficiencies. In severe cases, intravenous folate may be necessary," says Routhenstein.

Is it Possible to Prevent Folate Deficiency?

Woman sitting in a doctor's office talking with physician.

The experts say that it's also possible to prevent a folate deficiency before it begins. Routhenstein recommends getting started by consuming a balanced diet rich in folate-containing foods, such as leafy greens, legumes, citrus fruits, fortified grains, and by taking a folate supplement and prenatal vitamins if you are pregnant.

"Regularly monitoring your folate levels and maintaining a consistent intake of folate can also help prevent folate deficiency," she says. "It is important to know if you have increased folate requirements and adequately consume enough to prevent deficiency."


It's important for everyone to consume, absorb, and utilize enough folic acid. If you're presenting with symptoms suggestive of a deficiency, you should speak with your doctor to request blood serum testing or other related testing to confirm it. By altering your diet, beginning a regimen of folic acid supplements, and treating any underlying causes, you're likely to see improvements in your symptoms and condition.

Lauren Gray
Lauren Gray is a New York-based writer, editor, and consultant. Read more
Filed Under
Sources referenced in this article
  1. Source:
  2. Source:
  3. Source:
  4. Source:
  5. Source:
  6. Source: