How do you feel if you lack folic acid? The Physical and Mental Toll

November 14, 2025 •

3 min read

According to the Cleveland Clinic, one of the first and most common symptoms of folate deficiency is extreme tiredness. This can progress to a wider range of physical and mental health issues, impacting how you feel if you lack folic acid, from constant fatigue and irritability to more severe conditions like megaloblastic anemia.

Quick Summary

Explore the array of physical and mental symptoms that arise from a lack of folic acid, including persistent fatigue, mood changes, and other systemic effects. Uncover the common causes, potential complications, and effective ways to restore your body's folate levels.

Key Points

Extreme Tiredness: Persistent fatigue that doesn't improve with rest is one of the earliest signs of a folic acid deficiency.
Mood and Mental Health: Low folate levels are strongly linked to depression, anxiety, and general irritability.
Neurological Symptoms: Memory loss, difficulty concentrating, and 'pins and needles' sensations can be signs of the deficiency affecting your nervous system.
Anemia is Common: A lack of folic acid often leads to megaloblastic anemia, which causes paleness, weakness, and shortness of breath.
Diet and Supplements are Key: Treatment typically involves eating folate-rich foods like leafy greens and legumes, along with taking supplements prescribed by a doctor.
Distinct from B12 Deficiency: While symptoms overlap, folate deficiency does not cause the severe, irreversible nerve damage associated with B12 deficiency.

The Physical Toll: Common Symptoms of Low Folate

Megaloblastic anemia, characterized by large, fewer red blood cells, is a common result of folate deficiency. This affects the body's oxygen transport.

Chronic Fatigue and Weakness: A primary symptom, often described as persistent tiredness.
Pale Skin: May occur due to fewer red blood cells.
Shortness of Breath: Difficulty breathing, especially during activity, due to reduced oxygen.
Dizziness and Lightheadedness: Can result from insufficient oxygen to the brain.
Heart Palpitations: The heart may beat faster or irregularly.
Oral Symptoms: Sore, red tongue and mouth ulcers are frequent.
Digestive Issues: Diarrhea, loss of appetite, and weight loss are possible.

The Mental and Neurological Impact

Low folate can also affect mental health, as it's involved in neurotransmitter production.

Mood Changes: Irritability, depression, and anxiety are linked to low folate.
Cognitive Impairment: Difficulty concentrating, memory issues, and confusion ('brain fog') can occur.
Nervous System Issues: Peripheral neuropathy can cause numbness, tingling, and muscle weakness.

Causes of Folic Acid Deficiency

Various factors contribute to folate deficiency, with diet being a major cause.

Poor Diet: Low intake of folate-rich foods like leafy greens, citrus fruits, and legumes can cause deficiency within months.
Excessive Alcohol Consumption: Interferes with folate absorption.
Malabsorption Issues: Conditions like Crohn's or celiac disease hinder absorption.
Certain Medications: Some drugs can impair folate absorption.
Increased Demand: Pregnancy, breastfeeding, or certain blood disorders increase the need for folate.

Potential Complications of Untreated Deficiency

Untreated deficiency can lead to serious health problems.

Neural Tube Defects: A significant risk during pregnancy, leading to birth defects.
Cardiovascular Disease: Associated with higher homocysteine levels caused by low folate.
Infertility: Can be linked to folate deficiency.
Increased Cancer Risk: Some studies suggest a connection to certain cancers.

Folate vs. Folic Acid: What's the Difference?

Folate is the natural form in food, while folic acid is the synthetic form in supplements and fortified foods. Folic acid is more easily absorbed and used for fortification and supplements, especially for pregnant individuals.

Comparison of Folate and B12 Deficiency Symptoms


Symptom	Folate Deficiency	B12 Deficiency	Notes
Fatigue	Very common.	Very common.	Both cause megaloblastic anemia and tiredness.
Oral Issues	Sore tongue and mouth ulcers.	Sore tongue and mouth ulcers.	Similar oral symptoms.
Neurological Issues	Depression, confusion, memory problems.	Similar mental issues, plus potential irreversible nerve damage (tingling, numbness).	Folic acid can mask B12 deficiency and potentially worsen nerve damage.
Mental Health	Mood changes, irritability, anxiety.	Anxiety, confusion, can lead to dementia.	Both are important for mental well-being.
Speed of Onset	Can develop in a few weeks.	Often develops over months to years.	B12 is stored in larger amounts than folate.

Restoring Your Folate Levels: Diet and Supplements

Restoring folate levels involves diet and supplements.

Dietary Sources: Eat folate-rich foods like leafy greens, legumes, citrus fruits, and fortified cereals. Cooking methods like steaming help retain folate.
Supplements: Folic acid supplements are often prescribed to correct deficiency. Dosage should be determined by a healthcare provider. Supplements are vital during pregnancy.
Address Underlying Conditions: Treating any underlying cause is crucial for recovery.

For more information, see the Cleveland Clinic: Folate Deficiency: Symptoms, Causes & Prevention.

Conclusion: Listen to Your Body's Signals

Lacking folic acid presents a range of physical and mental symptoms, from fatigue and irritability to neurological issues. Recognizing these signs is key for early treatment. Understanding how you feel if you lack folic acid empowers you to seek diagnosis and treatment through diet, supplementation, and medical consultation. Correcting the deficiency can significantly improve health and quality of life.

Frequently Asked Questions

The most common initial symptom is extreme tiredness or fatigue that persists despite adequate rest. Other early signs can include irritability, weakness, and a lack of energy.

Yes, low levels of folate have been linked to mood disorders such as depression and anxiety. This is because folate is involved in producing neurotransmitters that regulate mood.

Since the body stores only a small amount of folate, a diet lacking in this vitamin can lead to a deficiency in just a few months. This is in contrast to B12 deficiency, which can take years to develop.

Folate is the natural form of vitamin B9 found in foods like leafy vegetables. Folic acid is the synthetic, man-made version that is used in supplements and fortified foods.

A folate deficiency can cause a condition called glossitis, where the tongue becomes sore, red, and swollen. It is also associated with painful mouth ulcers.

Foods rich in folate include dark leafy greens (spinach, kale), legumes (lentils, peas, beans), citrus fruits, asparagus, broccoli, and fortified grains like cereal and bread.

Yes, it is possible to have a folate deficiency without having developed full-blown megaloblastic anemia. Many of the neurological and psychological symptoms can appear before changes in red blood cell count become severe.