Does B1 Lower Anxiety? Understanding Thiamine's Role in Mental Health

December 6, 2025 •

4 min read

Research suggests that deficiencies in B vitamins can create a reinforcing cycle, where low levels may trigger anxiety symptoms and anxiety itself can deplete vitamin stores. Thiamine, or vitamin B1, is an essential nutrient crucial for nerve health and brain function, leading many to question its direct impact on anxiety.

Quick Summary

Thiamine (B1) is vital for nervous system energy and neurotransmitter function. While correcting a deficiency may alleviate anxiety-like symptoms such as fatigue and irritability, direct proof of B1 significantly lowering anxiety in non-deficient individuals is mixed. Combination B-complex often shows more promising results for stress and mood.

Key Points

Indirect Anxiety Relief: While B1 does not directly act as a primary anxiety-reducing agent, correcting a deficiency can alleviate associated symptoms like irritability and fatigue.
Nervous System Fuel: Thiamine is essential for energy production in nerve cells, especially in the brain, helping to support overall nervous system function.
Deficiency Mimics Anxiety: Symptoms of thiamine deficiency, such as confusion, irritability, and poor memory, often overlap with and can worsen anxiety.
B-Complex Synergy: Research indicates that taking a combination of B vitamins (B-complex) is often more effective for mood and stress than isolated B1.
Supports Stress and Sleep: Some studies show that B1 supplementation can help reduce stress and improve sleep quality, which are factors linked to anxiety.
Dietary Sources are Key: A balanced diet rich in whole grains, legumes, and lean meats is the best way to maintain optimal thiamine levels.

The Connection Between B1 and the Nervous System

Vitamin B1, also known as thiamine, is a water-soluble vitamin essential for energy metabolism throughout the body. Nerve cells require significant energy, and thiamine is critical for converting carbohydrates into usable energy for these cells. Adequate thiamine is necessary for proper neurological function.

Thiamine supports the nervous system through key functions, including energy production for nerve cells and involvement in neurotransmitter synthesis. Low levels of thiamine can impair neurological function and lead to symptoms that may resemble or worsen anxiety.

B1 Deficiency and Anxiety-Related Symptoms

Thiamine deficiency can result in symptoms like irritability, fatigue, and memory issues, often associated with dry beriberi. These symptoms can sometimes be mistaken for other mental health conditions. Symptoms linked to low thiamine levels include:

Irritability or changes in mood
Fatigue
Difficulty concentrating
Confusion and memory issues
Loss of appetite
Potential increase in anxiety due to neurotransmitter imbalances

Research Findings: What the Studies Say

The evidence regarding B1's direct impact on anxiety is inconsistent. Some studies suggest benefits, particularly when addressing a deficiency, while others do not show a significant effect on anxiety levels in those without a deficiency.

A 2025 trial combining B1 and B2 did not find a significant reduction in anxiety but did observe reduced stress, improved sleep, and less daytime sleepiness.
A small study on GAD patients with low thiamine levels showed improved anxiety scores after thiamine supplementation. This suggests that correcting a deficiency can be beneficial.
Animal research using thiamine compounds indicated improved anxiety-like behavior in a PTSD model.
Many experts highlight the benefits of B vitamins working together. A B-complex is often recommended for overall brain health and mood support over a single vitamin.

B1 vs. Other Nutrients for Anxiety Relief

Comparing B1 to other nutrients known to influence anxiety provides useful context. While B1 fuels the nervous system, other nutrients may have more direct calming effects.


Nutrient	Primary Mechanism	Evidence for Anxiety	Role of B1
Thiamine (B1)	Energy production for nervous system, neurotransmitter synthesis.	Mixed; effective for deficiency-related symptoms, less direct evidence for anxiety reduction in non-deficient individuals.	Corrects underlying metabolic issues that may cause anxiety-like symptoms.
Magnesium	Regulates stress response, influences GABA neurotransmitters.	Strong; deficiency is linked to higher anxiety and supplementation can help promote calmness.	Supports overall nerve function, but does not have the same direct calming effect.
Omega-3s	Reduces inflammation, essential for brain health.	Good; low intake linked to increased anxiety and depression.	A complementary nutrient, works through different anti-inflammatory pathways.
Vitamin B6	Cofactor for serotonin and GABA production.	Strong; high-dose supplementation linked to reduced self-reported anxiety by increasing GABA levels.	Works alongside B6 and other B vitamins in a synergistic way.

Food Sources and Supplementation

Most individuals can get enough thiamine from their diet, though some populations may need supplements. Thiamine is water-soluble and needs consistent intake.

Good Dietary Sources of Thiamine (B1):

Meats and Fish: Pork, salmon, and liver.
Legumes: Lentils, black beans, and other beans.
Whole Grains: Brown rice, oatmeal, and fortified products.
Seeds: Sunflower seeds and pecans.
Other: Green peas, nuts, and enriched pasta.

Considerations for Supplements: For general stress or mental wellness, a B-complex is often preferred over isolated B1 due to the synergistic effects of B vitamins. Targeted thiamine supplementation may be recommended by a healthcare provider for diagnosed deficiencies. Always consult a doctor before starting supplements, especially if on other medications. A balanced multivitamin or B-complex supports overall nervous system health. Additional information on thiamine is available from resources like the {Link: NIH Fact Sheets https://ods.od.nih.gov/factsheets/Thiamin-HealthProfessional/}.

Conclusion: Does B1 Lower Anxiety?

Vitamin B1 is essential for nervous system energy and metabolism and can indirectly help manage anxiety, especially if a deficiency is present. Supplementing with thiamine may ease anxiety-like symptoms caused by a deficiency, but it is not a proven direct treatment for anxiety in healthy individuals. A balanced diet, B-complex supplement, and healthy lifestyle practices offer the most comprehensive approach to mental wellness and stress reduction. Consult a healthcare professional to identify the cause of anxiety and determine the best treatment.

How to Supplement for Better B1 Absorption

With Food: Taking B-complex supplements with a meal can enhance absorption and minimize stomach upset.
Separate from Coffee/Tea: Avoid consuming coffee or tea at the same time as supplements due to tannins that can hinder thiamine absorption.
Choose Bioavailable Forms: Discuss different supplement forms with a healthcare provider.

Final Recommendations

Prioritize Diet: Focus on foods rich in B vitamins like whole grains, pork, and legumes.
Consider B-Complex: For supplementation, a B-complex often provides more comprehensive support for the nervous system.
Check for Deficiency: If you have anxiety-like symptoms, consult a doctor to rule out nutritional deficiencies.
Adopt a Holistic Approach: Combine nutrition with exercise, stress management, and sleep for optimal results.

Frequently Asked Questions

Low vitamin B1 (thiamine) deficiency can cause symptoms such as irritability, fatigue, and neurological issues that can manifest as or worsen anxiety. It can disrupt the balance of calming and excitatory neurotransmitters, contributing to a state of heightened anxiety.

Yes, many studies suggest that the B vitamins work synergistically. A B-complex supplement is often more beneficial for overall brain health and mood support, and studies using B-complex often show more pronounced effects on stress and mood compared to isolated B1.

Good dietary sources of thiamine include pork, salmon, black beans, lentils, whole grains like brown rice and oatmeal, and fortified cereals. Seeds like sunflower and pecans also provide thiamine.

Yes, thiamine plays a vital role in the synthesis of several neurotransmitters, including serotonin and GABA. An imbalance in these brain chemicals due to B1 deficiency can negatively impact mood regulation.

Excessive thiamine intake is not typically linked to anxiety, as thiamine is a water-soluble vitamin and excess is excreted. In rare cases, extremely high doses might cause restlessness, but deficiency is the more common cause of mood disturbances.

The timeline can vary based on the severity of the deficiency. Some studies have noted improvements in deficiency-related symptoms, such as fatigue and mood, within weeks of supplementation. For general wellness, a longer period of consistent intake may be required.

The primary function of thiamine is to serve as a coenzyme in the metabolism of carbohydrates, providing the energy that nerve cells, particularly in the brain, need to function correctly.