What Causes You to Be Low on Folic Acid?

November 21, 2025 •

4 min read

According to the CDC, all women capable of becoming pregnant need 400 micrograms of folic acid daily. A deficiency, however, can happen to anyone and can stem from a variety of underlying issues, including poor diet and certain medical conditions. Understanding what causes you to be low on folic acid is the first step toward correcting the problem and preventing related health complications.

Quick Summary

This article explores the various causes of low folic acid levels, from inadequate dietary intake and impaired absorption to increased bodily requirements and specific medical conditions. It details how certain medications and lifestyle factors can also contribute to a deficiency, providing an in-depth look at the contributing factors.

Key Points

Poor Diet: Not eating enough folate-rich foods like leafy greens, legumes, and fortified grains is a primary cause of low folic acid.
Malabsorption Issues: Conditions such as celiac disease and Crohn's disease can impair the small intestine's ability to absorb folate.
Increased Physiological Needs: Pregnancy, lactation, and certain chronic diseases like hemolytic anemia dramatically increase the body's demand for folate.
Alcohol Consumption: Excessive alcohol use interferes with folate absorption and metabolism, often correlating with poor nutritional intake.
Medication Interference: Some drugs, including certain anticonvulsants and methotrexate, can negatively impact folate levels.
Genetic Factors: A mutation in the MTHFR gene can hinder the body's ability to convert folic acid into its active form, making supplementation challenging.
Cooking Practices: Overcooking vegetables can destroy the natural folate content, reducing your overall intake.

Poor Diet: A Common Culprit

One of the most straightforward reasons someone might be low on folic acid is a diet lacking in folate-rich foods. Since the body does not store large reserves of folate, a consistent intake is crucial. Folic acid is the synthetic, more easily absorbed form of folate, and it's added to many fortified grains in some countries, but inadequate consumption remains a primary cause, especially in populations without access to fortified foods.

Foods High in Folate

To prevent dietary deficiency, it's important to include folate-rich foods regularly. Good sources include:

Leafy Greens: Spinach, kale, romaine lettuce
Legumes: Lentils, peas, black-eyed peas, kidney beans
Fortified Grains: Enriched bread, rice, pasta, and some cereals
Fruits: Oranges, citrus fruits, and bananas
Other Sources: Liver, eggs, and nuts

Cooking Methods Matter

Folate is highly sensitive to heat, and prolonged or excessive cooking can destroy up to 95% of the vitamin in food. This means that even if you consume plenty of folate-rich vegetables, improper cooking can severely reduce the amount your body receives. Steaming, microwaving, or lightly stir-frying vegetables helps preserve more of the folate content.

Medical Conditions Affecting Absorption

Beyond diet, several medical conditions can impair the body's ability to absorb or use folic acid effectively. These issues often arise in the digestive system, where folate is absorbed.

Gastrointestinal Disorders

Certain diseases that affect the small intestine can hinder nutrient absorption. These include:

Celiac Disease: An autoimmune disorder where consuming gluten damages the small intestine lining, impeding absorption.
Crohn's Disease and Inflammatory Bowel Disease (IBD): These inflammatory conditions can interfere with the gut's ability to absorb vitamins.
Bariatric Surgery: Procedures that reduce the size of the stomach or bypass parts of the intestine can decrease the area available for absorption.

Vitamin B12 Deficiency

An interesting and important cause is an underlying deficiency of Vitamin B12. Folate and B12 work together in the body's metabolic processes. If B12 is deficient, a mechanism known as the "folate trap" can occur, where folate becomes trapped in an unusable form, leading to functional folate deficiency even if intake is sufficient. This is why doctors often test for both deficiencies simultaneously. A vitamin B12 deficiency needs to be treated before or alongside a folic acid deficiency to prevent neurological complications.

Increased Bodily Requirements

For certain groups of people, the body's need for folate increases significantly, and standard intake may not be enough to prevent deficiency.

Pregnancy and Lactation

This is perhaps the most well-known instance of increased folate requirements. Rapid cell division and fetal development during pregnancy significantly elevate the demand for folate. This is why supplementation is widely recommended before and during pregnancy to prevent neural tube defects. Lactating women also have higher needs.

Chronic Health Conditions

Conditions that involve high cell turnover can increase the body's folate demands. These include:

Hemolytic Anemia: A blood disorder where red blood cells are destroyed faster than they can be replaced.
Malignancy (Cancer): Increased cell turnover during some cancers can increase folate utilization.
Exfoliative Skin Disorders: Rapid regeneration of skin cells in conditions like severe psoriasis can raise folate needs.

Medications and Genetic Factors

Certain medications can interfere with folate absorption or metabolism. For example, some anti-seizure medications, methotrexate, and sulfasalazine are known to cause a deficiency. Additionally, some people have a genetic mutation, such as the MTHFR gene variation, which impairs their ability to convert folic acid into its active, usable form. This means that standard folic acid supplements may be less effective for these individuals, who might require a different form of supplementation.

Comparison of Key Folic Acid Deficiency Causes


Cause	Mechanism	Impact	Management
Poor Diet	Insufficient intake of folate-rich foods.	Deficiency can develop in a few months without adequate intake.	Increase consumption of green leafy vegetables, legumes, and fortified grains.
Malabsorption	Intestinal diseases like celiac or Crohn's prevent proper absorption.	Body cannot absorb folate even with sufficient intake.	Treat the underlying disease and consider high-dose supplementation.
Increased Demand	Rapid cell growth during pregnancy, lactation, or illness.	Body uses more folate than it can intake, leading to a deficit.	Supplementation is often required to meet the higher demand, especially during pregnancy.
Alcoholism	Impairs absorption and metabolism; often linked to poor diet.	Chronic consumption significantly depletes folate levels.	Reduce alcohol intake and use supplements to restore levels.
Medications	Certain drugs block absorption or interfere with metabolism.	Drug interactions lead to decreased folate availability.	Consult a doctor; dosage adjustments or alternative medications may be necessary.
Genetic Factors	MTHFR gene mutation affects conversion to active folate.	Impairs the body's ability to utilize folic acid effectively.	May require supplements with the active form of folate (L-methylfolate).

Conclusion

Being low on folic acid is a condition with multiple potential causes, ranging from controllable dietary factors to complex medical issues. A poor diet, malabsorption due to intestinal conditions, excessive alcohol consumption, and increased physiological needs during pregnancy or chronic illness are all significant contributing factors. Certain medications and specific genetic mutations can also disrupt the body's folate levels and metabolism. Because of the varied nature of its causes, an accurate diagnosis by a healthcare professional is essential for determining the root cause and establishing an effective treatment plan, which may involve dietary changes, supplements, or managing underlying health conditions. This comprehensive approach ensures that the deficiency is properly addressed and prevents potential health complications.

Authoritative Outbound Link

For a deeper understanding of folate metabolism and its role in human health, you can refer to the National Institutes of Health's Folate fact sheet: Folate Fact Sheet for Health Professionals.

Frequently Asked Questions

The first signs of low folic acid often include fatigue, weakness, and a general lack of energy. You may also experience irritability, a sore tongue, or mouth ulcers.

While neurological symptoms are more common with B12 deficiency, folate deficiency can lead to mood changes like depression, irritability, or cognitive difficulties, although it typically doesn't cause the classic nerve damage seen in B12 deficiency.

Yes, a mutation in the MTHFR gene can impair the body's ability to convert folic acid into its active form. Individuals with this mutation may require a different type of folate supplement to effectively raise their levels.

With proper supplementation, blood markers of folate deficiency, like macrocytic anemia, typically begin to resolve within 1 to 2 weeks, with full resolution within 4 to 8 weeks.

In countries with mandatory food fortification, like the US, fortified foods such as bread and cereals significantly contribute to the average folic acid intake. However, for those with higher needs (e.g., during pregnancy) or absorption issues, supplements are often necessary.

Yes, chronic and excessive alcohol consumption is a major cause of low folic acid. Alcohol interferes with folate absorption and metabolism and is often associated with poor dietary habits.

Folate is the naturally occurring form of vitamin B9 found in food. Folic acid is the synthetic, man-made form that is used in fortified foods and dietary supplements. Folic acid is more easily absorbed by the body.