How do you treat low B9 levels?

January 11, 2026 •

4 min read

According to the Centers for Disease Control and Prevention (CDC), mandatory food fortification has significantly reduced folate deficiency in many countries. If you suspect you may have low B9 levels, the primary treatments involve dietary modifications, folic acid supplementation, and addressing any underlying medical issues.

Quick Summary

Treating low B9 levels typically involves a combination of dietary adjustments and folic acid supplementation. A medical diagnosis is essential to determine the appropriate approach and rule out a concurrent B12 deficiency. Treatment often lasts several months, with an emphasis on addressing underlying causes for long-term health.

Key Points

Medical Consultation is Essential: Always see a healthcare provider for a proper diagnosis and to check B12 levels before beginning folic acid treatment.
Boost Diet with Folate-Rich Foods: Incorporate leafy greens, legumes, citrus fruits, and fortified grains into your meals to naturally increase B9 intake.
Use Folic Acid Supplements as Directed: Follow your doctor's prescribed guidance for folic acid tablets, which are generally well-absorbed.
Check Vitamin B12 Levels First: Folic acid can mask a B12 deficiency, potentially leading to irreversible neurological damage, so screening for both is crucial.
Address Underlying Causes: Long-term resolution depends on treating any underlying issues like excessive alcohol use, malabsorption disorders, or reactions to medication.
Monitor Your Progress: Follow-up blood tests may be necessary to confirm treatment is working and that both B9 and hemoglobin levels are normalizing.

What is Vitamin B9 and Folate Deficiency?

Vitamin B9, known as folate in its natural form and folic acid in its synthetic form, is a crucial nutrient for the body. It plays a vital role in producing red and white blood cells, synthesizing DNA and RNA, and supporting rapid cell growth during pregnancy and infancy. A deficiency occurs when there isn't enough B9 to support these essential bodily functions, leading to conditions like megaloblastic anemia.

Symptoms of folate deficiency can include fatigue, pale skin, a red and sore tongue, irritability, shortness of breath, and mouth ulcers. However, as symptoms can be non-specific, a proper blood test is necessary for a definitive diagnosis.

Common causes of low B9 levels include:

Inadequate dietary intake: Not consuming enough folate-rich foods.
Excessive alcohol consumption: Alcohol interferes with folate absorption and metabolism.
Malabsorption disorders: Conditions like celiac disease or Crohn's disease hinder nutrient absorption.
Certain medications: Some anticonvulsants and other drugs can affect folate levels.
Increased physiological demand: Pregnancy and chronic hemolytic anemia increase the body's need for folate.

Dietary Adjustments for Folate Repletion

One of the most foundational steps to treat low B9 levels is to increase dietary intake of folate-rich foods. These foods provide the natural form of the vitamin and can be easily incorporated into your daily meals. It is important to note that cooking at high heat can destroy folate, so steaming or lightly cooking vegetables is preferable.

Folate-Rich Food Sources

Leafy Greens: Spinach, kale, and romaine lettuce are excellent sources.
Legumes and Beans: Lentils, black-eyed peas, chickpeas, and kidney beans are packed with folate.
Asparagus and Broccoli: These vegetables offer a significant folate boost.
Citrus Fruits: Oranges and orange juice contain natural folate.
Fortified Grains: Many breads, cereals, pasta, and rice products are enriched with folic acid.
Animal Products: Beef liver, poultry, and eggs also contain folate.

Folic Acid Supplementation

For many people with a diagnosed deficiency, dietary changes alone are not enough, and a doctor may recommend a folic acid supplement. Folic acid is the synthetic form of B9 and is generally well absorbed by the body. The specific amount and duration of supplementation will be determined by a healthcare provider based on the individual's needs and the severity of the deficiency.

Supplementation Protocol

Dosage: A healthcare provider will determine the appropriate amount based on individual factors. Pregnant women or those planning pregnancy often require specific amounts to prevent neural tube defects.
Duration: Treatment typically continues until blood counts and folate levels normalize. For ongoing underlying causes, longer-term or even lifelong supplementation might be necessary.
Route: Folic acid is commonly available as oral tablets, but other methods may be considered for severe cases or individuals with significant malabsorption.

Comparison: Natural Folate vs. Synthetic Folic Acid

While both natural folate and synthetic folic acid are forms of vitamin B9, they have some key differences important for treatment.


Feature	Natural Folate (in food)	Synthetic Folic Acid (in supplements/fortified foods)
Absorption	Less readily absorbed; about 50% bioavailability.	Higher bioavailability, especially on an empty stomach.
Stability	Easily destroyed by heat and sunlight during cooking and storage.	Highly stable; ideal for food fortification and supplements.
Source	Dark leafy greens, legumes, citrus fruits, liver.	Supplements and fortified grains like breads, cereals, pasta, and rice.
Medical Use	Part of a healthy diet, but usually insufficient to reverse a deficiency on its own.	Prescribed to treat deficiencies and prevent neural tube defects in pregnancy.
Metabolism	Metabolized through multiple steps into its active form, 5-MTHF.	Must be converted to 5-MTHF in the body; some people with an MTHFR gene variation may have trouble with this conversion.

The Critical Importance of Vitamin B12 Screening

Before starting folic acid supplementation, it is absolutely essential for a healthcare provider to check your vitamin B12 levels. The reason for this critical step is that folic acid can mask a co-existing vitamin B12 deficiency by correcting the anemia, but it will not prevent or reverse the potentially irreversible neurological damage caused by B12 deficiency. This is known as the "folate trap" phenomenon. Therefore, your doctor will always evaluate both B9 and B12 levels to ensure a safe and effective treatment plan.

The Role of Lifestyle and Addressing Underlying Conditions

For treatment to be successful and long-lasting, it is vital to address the root cause of the deficiency. For example, if excessive alcohol use is the problem, reducing or stopping consumption is necessary. For those with malabsorption issues, treating the underlying digestive disorder (e.g., celiac disease) is paramount. A dietitian can also provide tailored dietary advice to ensure a sustainable intake of folate.

Conclusion

Treating low B9 levels requires a multifaceted approach guided by a medical professional. Diagnosis with a blood test is the first step, followed by a personalized plan that typically combines oral folic acid supplementation with dietary changes. Always ensure vitamin B12 levels are checked concurrently to avoid masking a more serious deficiency. By following a doctor’s recommendations and addressing any underlying issues, it is possible to effectively resolve the deficiency, restore energy, and prevent long-term health complications.

For more information on folate and its health benefits, you can consult the NIH Office of Dietary Supplements.

Frequently Asked Questions

Folate is the naturally occurring form of vitamin B9 found in foods like leafy greens and legumes. Folic acid is the synthetic, more easily absorbed version used in supplements and fortified foods.

While a folate-rich diet is crucial for prevention and support, it is often not enough to reverse an existing deficiency. Folic acid supplementation, as prescribed by a doctor, is usually required for effective treatment.

For many individuals with a dietary deficiency, treatment with folic acid tablets typically lasts around four months. However, the duration may be longer depending on the severity and underlying cause.

A doctor must check your B12 levels because folic acid can mask a B12 deficiency. Treating with folic acid alone can correct the anemia symptoms while allowing potentially irreversible neurological damage from the untreated B12 deficiency to progress.

If your deficiency is caused by a malabsorption disorder, treating the underlying condition is vital for long-term success. Your doctor may also recommend specific treatment methods, sometimes administered via injection, for a longer duration.

Yes, some medications, such as certain anti-seizure drugs and methotrexate, can interfere with folate absorption. If this is the cause, your doctor will adjust your treatment plan accordingly.

Early signs can include fatigue, lack of energy, and general weakness. As the deficiency progresses, you may experience more pronounced symptoms like a sore tongue, mouth ulcers, and cognitive issues.