Does Vitamin B1 Relax You? Unpacking the Science of Thiamine for Stress

October 21, 2025 •

4 min read

According to a 2025 study published in MDPI, vitamin B1 and B2 supplementation helped reduce stress and enhance sleep in clinical trials, but had no significant impact on anxiety. This highlights the nuanced relationship between vitamin B1 and relaxation, and requires a deeper look into the science of how thiamine affects the body's stress response and nervous system.

Quick Summary

This article explains the role of vitamin B1 (thiamine) in nervous system function and its impact on stress. It clarifies that while it supports a healthy nervous system and energy metabolism, directly promoting relaxation, especially for well-nourished individuals, has limited evidence. Focus is placed on its role in deficiency states, where supplementation can significantly improve mood and stress-related symptoms. It covers dietary sources and contrasts its effects with other B vitamins for stress relief.

Key Points

Indirect Relaxation: Vitamin B1 does not directly induce relaxation like a sedative; its calming effect is indirect, stemming from its vital role in supporting a healthy nervous system and energy metabolism.
Addresses Deficiency Symptoms: Thiamine supplementation is most beneficial for stress and mood in individuals with a deficiency, where it can reverse symptoms like irritability, anxiety, and fatigue.
Synergy with Other B Vitamins: A B-complex supplement often provides broader benefits for stress and mood than thiamine alone, as other B vitamins like B6 and B12 are also crucial for neurotransmitter production.
Limited Evidence for Direct Effect: In healthy, well-nourished individuals, robust scientific evidence is lacking for a significant, direct psychological relaxation effect from thiamine supplementation.
Dietary Intake is Key: The best way to maintain healthy thiamine levels is through a diet rich in foods like pork, fish, legumes, nuts, and whole grains.
Reduces Perceived Stress: While a 2025 study showed no significant impact on anxiety, it did find that vitamin B1 supplementation helped reduce perceived stress and improve sleep quality.
Critical for Brain Energy: Thiamine ensures the brain and nervous system have a constant energy supply by helping convert carbohydrates into fuel, a fundamental process for maintaining mood stability.

Understanding Vitamin B1 and the Nervous System

Vitamin B1, or thiamine, is a water-soluble vitamin that plays a critical role in the body's energy metabolism. Its primary function is to help convert carbohydrates into energy, which is essential for the proper functioning of the brain and nervous system. Nerve cells require a constant supply of energy to function correctly, and thiamine acts as a crucial coenzyme in this process. Beyond energy, thiamine is also involved in the synthesis of certain neurotransmitters, which are the chemical messengers of the brain that regulate mood and psychological function. The link between thiamine and stress and relaxation, therefore, is primarily an indirect one, working through its foundational support of the nervous system.

The Link Between Thiamine Deficiency and Stress-Related Symptoms

One of the most compelling arguments for thiamine's influence on relaxation and mood comes from understanding the symptoms of a deficiency. A lack of sufficient thiamine can significantly impair nervous system function, leading to a host of psychological and neurological symptoms that mimic or exacerbate stress.

Symptoms of a mild thiamine deficiency can include:

Fatigue and low energy levels
Irritability and mood shifts
Poor memory and concentration
Anxiety and mood disorders
Sleep disturbances

In severe deficiency cases, such as beriberi or Wernicke-Korsakoff syndrome, neurological damage can be significant. For individuals with a subclinical or marginal thiamine deficiency, supplementation can lead to a marked improvement in these symptoms, which in turn promotes a greater sense of well-being and, indirectly, relaxation. However, this is different from the effect in an otherwise healthy, well-nourished person. The feeling of "relaxation" is often a return to normalcy after addressing the underlying deficiency, rather than a direct, calming effect.

The Role of a B-Complex Over Individual Vitamins

While vitamin B1 is important, it's part of a larger team of B vitamins that work together synergistically. Many B-complex supplements are marketed for stress reduction because the entire complex supports nervous system function and energy metabolism. Some B vitamins, in particular, may have a more direct impact on stress and anxiety than thiamine alone. For instance, Vitamin B6 helps produce the calming neurotransmitter GABA, and B12 is also critical for mood regulation.

Evidence for Vitamin B1 and Stress

The scientific literature presents a nuanced picture regarding vitamin B1 and stress. While historical tradition included thiamine in "stress" formulas, robust clinical research specifically proving its relaxation benefits in healthy individuals is limited. Much of the evidence stems from studies focusing on deficiency states.

Deficiency Studies: Studies on thiamine deficiency consistently show that supplementing with thiamine reverses neurological and psychological symptoms, including irritability and poor mood, thereby improving overall well-being.
Recent Clinical Trials: A recent 2025 study explored the effect of vitamin B1 and B2 supplementation on anxiety and stress. While the supplements did reduce perceived stress and enhance sleep quality compared to a placebo group, they had no significant effect on anxiety levels directly. This suggests B1's role may be more about supporting the body's resilience to stress rather than actively mitigating anxiety.

Comparison of B Vitamins for Stress and Relaxation


Feature	Vitamin B1 (Thiamine)	Vitamin B6 (Pyridoxine)	Vitamin B12 (Cobalamin)
Primary Role for Stress	Supports nervous system energy and function; addresses deficiency symptoms like irritability and fatigue.	Aids in the production of neurotransmitters like serotonin and GABA, which have a calming effect.	Critical for mood regulation and nerve health; deficiency is linked to depression and anxiety.
Relaxation Mechanism	Indirect; by optimizing energy metabolism and correcting deficiency-related nervous system impairments.	Direct; by facilitating the synthesis of calming neurotransmitters.	Indirect; by supporting overall nerve health and mood-regulating neurotransmitters.
Effect in Healthy People	Limited evidence for direct psychological stress relief; more impactful in cases of marginal or subclinical deficiency.	Some studies suggest benefits for anxiety and stress even in well-nourished individuals, often in higher doses.	Adequate levels support mood stability, preventing mood changes associated with deficiency.

Dietary Sources and Considerations

The best way to ensure adequate thiamine levels is through a balanced diet. Thiamine is a water-soluble vitamin, so it's not stored in the body and must be consumed regularly. Cooking can reduce thiamine content, particularly when boiling foods, as the vitamin leaches into the water.

Excellent dietary sources of thiamine include:

Pork and Fish: Lean meats like pork and salmon are rich in thiamine.
Legumes and Nuts: Black beans, lentils, and sunflower seeds are great plant-based sources.
Whole Grains: Whole grain bread, fortified cereals, and brown rice contain good amounts.
Other Sources: Peas, eggs, and fortified pasta also contribute to your intake.

Conclusion: A Supportive Role, Not a Direct Relaxant

So, does vitamin B1 relax you? The most accurate answer is that it plays a vital supportive role rather than acting as a direct sedative or relaxant. By ensuring your nervous system has the energy it needs to function correctly, thiamine helps maintain your body's resilience to stress. For individuals with a deficiency, supplementing thiamine can dramatically reduce stress-related symptoms like irritability and fatigue, leading to a greater sense of calm and well-being. However, for those who are already well-nourished, the evidence for a direct relaxing effect is not as strong. A holistic approach that includes a varied diet rich in all B vitamins, alongside other stress management techniques, is the most effective strategy for promoting overall mental and physical health.

Here is a helpful resource from the National Institutes of Health with more information on thiamine.

Frequently Asked Questions

Vitamin B1, also known as thiamine, is a water-soluble vitamin essential for energy metabolism, particularly for the brain and nervous system. It helps convert carbohydrates into usable energy for the body.

Yes, thiamine deficiency has been linked to increased anxiety, irritability, and other mood disturbances. By supporting nervous system function, maintaining adequate levels can help regulate mood and improve stress tolerance.

Historically, some have referred to vitamin B1 as the 'anti-stress' vitamin, particularly in traditional supplements. This is primarily because deficiency symptoms mimic stress, and supplementing in a deficient state can alleviate these issues.

Good food sources include pork, salmon, black beans, lentils, nuts (especially sunflower seeds), whole grains, and fortified cereals.

Unlike vitamin B6, which directly aids in producing calming neurotransmitters like GABA, vitamin B1's effect on mood is more indirect. It supports the foundational energy needs of the nervous system, with its most noticeable mood-boosting effect occurring when a deficiency is corrected.

A B-complex supplement is generally more comprehensive for overall nervous system support, as B vitamins work synergistically. Other B vitamins like B6 and B12 may have more specific and direct effects on anxiety and mood regulation.

As a water-soluble vitamin, excess thiamine is typically excreted through urine, and there is no known upper limit for toxicity. However, consulting a healthcare professional before starting any new supplement regimen is always recommended.