Understanding the Symptoms You Have with Low Folic Acid

January 6, 2026 •

3 min read

According to the CDC, folate fortification of food in the United States has led to a significant decrease in birth defects, yet many people can still experience low levels of this essential B vitamin. A deficiency can cause a range of subtle but debilitating symptoms that impact daily life and overall health.

Quick Summary

Low folic acid, or folate, levels can lead to various physical and mental health issues, including fatigue, muscle weakness, and neurological problems. The deficiency often results in megaloblastic anemia, affecting red blood cell production. Common signs also include oral issues and cognitive changes.

Key Points

Fatigue and Weakness: Low folic acid often leads to anemia, causing persistent and unexplained tiredness and lack of energy.
Neurological Problems: Nerve-related issues like numbness, tingling (pins and needles), and cognitive difficulties are common symptoms.
Oral Manifestations: A sore, swollen tongue and mouth ulcers are characteristic signs of a folate deficiency.
Megaloblastic Anemia: The deficiency causes the production of abnormally large red blood cells, which can't transport oxygen efficiently.
Mood Changes: Irritability, depression, and other psychological problems are linked to insufficient folate levels.
Cardiac Effects: The heart may work harder to circulate oxygen, leading to palpitations and shortness of breath.
Diagnosis is Vital: It is crucial to test for both folate and vitamin B12 deficiencies, as symptoms overlap but treatments differ.

Common Symptoms of Low Folic Acid

Folate, also known as vitamin B9, is critical for numerous bodily functions, including DNA synthesis and cell division. When levels are too low, the most common consequence is megaloblastic anemia, where the body produces abnormally large, immature red blood cells that cannot function properly. This impairs the delivery of oxygen throughout the body and causes many of the most recognizable symptoms of low folic acid. Symptoms often develop gradually and can mimic other conditions, making proper diagnosis essential.

Anemia-Related Symptoms

Persistent Fatigue and Weakness: A lack of healthy red blood cells means less oxygen is delivered to your body's tissues and muscles, causing you to feel unusually tired and weak. This fatigue is not typically relieved by rest.
Pale Skin: Reduced oxygenated blood flow can lead to pallor, or a pale appearance, especially noticeable on the skin.
Shortness of Breath and Heart Palpitations: To compensate for the lack of oxygen, the heart may beat faster and harder, leading to palpitations or a feeling of breathlessness, particularly during physical activity.

Neurological and Cognitive Symptoms

Since folate is vital for maintaining a healthy nervous system, a deficiency can significantly impact neurological function.

Numbness and Tingling: Often described as a "pins and needles" sensation, this symptom is a result of nerve damage caused by the deficiency.
Cognitive Decline: Low folate can cause problems with memory, concentration, and judgment, sometimes leading to confusion. Some severe, long-term cases have been linked to an increased risk of dementia.
Mood Changes and Depression: Psychological symptoms, including irritability and depression, have been associated with low folate levels.

Oral and Digestive Symptoms

Folate deficiency also manifests with distinct symptoms affecting the mouth and digestive system.

Red, Sore Tongue: A swollen, beefy-red, and tender tongue is a classic sign of folate deficiency.
Mouth Sores: Mouth ulcers or sores can frequently appear.
Reduced Sense of Taste: The taste buds can be negatively affected, leading to a diminished sense of taste.
Diarrhea and Weight Loss: Digestive issues like diarrhea and a resulting loss of appetite and weight can occur.

Low Folic Acid vs. Vitamin B12 Deficiency Symptoms

It is crucial to differentiate between low folic acid and vitamin B12 deficiency, as they can cause similar symptoms but require different treatment approaches. Correcting a B12 deficiency with folic acid alone can mask the B12 issue and lead to irreversible neurological damage.


Symptom Category	Low Folic Acid	Vitamin B12 Deficiency
Anemia	Megaloblastic Anemia (large red blood cells)	Megaloblastic Anemia (large red blood cells)
Neurological	Tingling, numbness, cognitive issues, mood changes	More severe neurological symptoms, including irreversible nerve damage
Oral Health	Red, sore tongue; mouth ulcers; reduced taste	Similar oral symptoms, but potentially more severe
Onset of Symptoms	Symptoms can appear within weeks	Symptoms typically develop more slowly over months or years
Primary Cause	Poor diet, malabsorption issues, alcoholism	Diet (less common), pernicious anemia, stomach issues

Causes and Diagnosis

Besides an inadequate diet, several factors can cause low folic acid. Alcoholism interferes with folate absorption, and conditions like celiac disease or Crohn's disease can lead to malabsorption. Certain medications, including some for rheumatoid arthritis and epilepsy, can also impact folate levels. In some cases, a genetic mutation (MTHFR polymorphism) can prevent the body from converting folate into its active form.

To diagnose a deficiency, a doctor can perform a blood test to measure the folate level in your blood. This test helps differentiate it from B12 deficiency and confirms the diagnosis. Addressing the underlying cause is key to effective treatment.

Conclusion

Low folic acid can result in a wide array of symptoms, from debilitating fatigue and heart palpitations to neurological issues like numbness and cognitive problems. Many of these issues stem from megaloblastic anemia, which impairs oxygen delivery throughout the body. Distinguishing the signs of low folate from a B12 deficiency is crucial for proper treatment and to prevent long-term health complications. A balanced, nutrient-rich diet, and in some cases, supplementation, can often effectively reverse the symptoms and restore normal health. If you suspect a deficiency, consulting a healthcare provider for a proper diagnosis is the first and most important step toward recovery. For more information on dietary needs, you can refer to the CDC recommendations on folic acid.

Frequently Asked Questions

Folate is the naturally occurring form of vitamin B9 found in foods like leafy greens and citrus fruits, while folic acid is the synthetic form used in fortified foods and supplements.

Because the body stores only a limited amount of folate, a deficiency can develop within a few weeks to months if dietary intake is insufficient.

Yes, a folate deficiency can lead to peripheral neuropathy, which can cause symptoms such as numbness and tingling in the hands and feet due to nerve damage.

Individuals with poor diet, alcohol use disorder, malabsorptive disorders like celiac disease, pregnant people, and those on certain medications are at a higher risk.

Yes, psychological problems, including depression and irritability, have been associated with folate deficiency.

A doctor can diagnose a folic acid deficiency with a simple blood test that measures the folate level in your blood.

While generally safe, high intakes of folic acid can mask a potentially dangerous vitamin B12 deficiency and may pose other health concerns, making medical supervision important.