4 Benefits of Thiamine Supplementation

When it comes to B vitamins, I can guarantee you that thiamine doesn’t get enough attention.

And compared to vitamin C or D, it gets even less attention.

However, that doesn’t mean it’s not an important vitamin to supplement with, and I’ll get into the guidelines for supplementation.

While thiamine doesn’t get the attention it deserves compared with vitamin D, magnesium, or omega-3s, it’s involved in some of the most basic work our cells do every day.

Thiamine, also known as vitamin B1, helps the body turn carbohydrates and other nutrients into usable cellular energy.

It supports normal nerve function and is particularly important to tissues with high energy demands, including the brain and heart.

Because thiamine is water-soluble and the body stores relatively little of it, we depend on a fairly regular dietary supply. Deficiency can occur with poor nutrition, prolonged vomiting, heavy alcohol use, bariatric surgery, certain gastrointestinal problems and, in some cases, chronic diuretic use.

When thiamine status is low, supplementation can make an enormous difference. In severe deficiency, it can even be lifesaving.

Here are four reasons I pay attention to it.

How Does Thiamine Supplementation Help?

Not everyone will need to take a thiamine supplement.

It’s usually only needed when a person is deficient.

Thiamine deficiencies can develop when the body doesn’t get enough, can’t absorb it well, or uses it up faster than usual.

Common causes for deficiency include poor nutrition, heavy alcohol use, prolonged vomiting, bariatric surgery, digestive disorders, and certain medications.

Because the body stores very little thiamine, deficiency can develop relatively quickly.

Now it’s time to tell you how it works and why supplementation can help.

1 - It Helps the Body Produce Energy:

Thiamine’s most fundamental job is helping cells extract energy from food.

In its active form, thiamine acts as a cofactor for enzymes involved in carbohydrate metabolism and mitochondrial energy production. Think of those enzymes as machinery in a power plant. Thiamine is one of the components required to keep that machinery running.

When thiamine becomes deficient, energy metabolism starts becoming inefficient. Pyruvate and lactate can accumulate, while cells—particularly energy-hungry cells have more difficulty producing what they need.

That can contribute to symptoms such as fatigue, weakness, poor appetite and exercise intolerance.

This doesn’t mean taking extra thiamine will act like a stimulant if your levels are already adequate. But when somebody is deficient, restoring thiamine gives the body back an essential tool it needs to make energy normally.

2 - It Supports the Brain and Nervous System:

The nervous system is particularly sensitive to inadequate thiamine because the brain depends heavily on continuous energy production.

More significant deficiency can lead to numbness, weakness, impaired coordination, confusion and other neurologic problems. 

At the severe end of the spectrum is Wernicke encephalopathy, an emergency classically associated with alcohol-use disorder but also seen after bariatric surgery, prolonged vomiting, malnutrition and other conditions.

Once neurologic thiamine deficiency is suspected, treatment shouldn’t be delayed unnecessarily. 

Reviews of thiamine-deficiency disorders describe improvement that can begin within hours or days after appropriate replacement, although established neurologic injury may take much longer to recover and may not always be completely reversible.

People who’ve undergone bariatric surgery are a group who absolutely need to assess levels.  A systematic review found meaningful rates of thiamine deficiency before and especially during the first several months after bariatric procedures.

3 - It Helps Maintain Normal Cardiovascular Function:

Severe thiamine deficiency can also affect the heart and circulation.

Historically this has been called wet beriberi. When thiamine becomes sufficiently depleted, the heart may struggle to meet the body’s metabolic demands, sometimes contributing to rapid heart rate, fluid retention and heart failure.

Correcting an actual deficiency can therefore dramatically improve cardiovascular problems caused by that deficiency.

But there’s an important distinction here.

Giving thiamine to everyone with heart failure hasn’t consistently improved heart function.

A 2024 meta-analysis of randomized trials found that supplementation corrected thiamine deficiency but didn’t significantly improve ejection fraction, walking ability or several other heart-failure outcomes overall.

I think that’s an excellent example of how supplements should be viewed.

When the body is missing something essential, replacement can be powerful.

More isn’t automatically better once the need has been met.

4 - It Supports Normal Glucose Metabolism:

Thiamine is also deeply involved in glucose metabolism. And those following my writing for the past decade know how much I focus on balancing blood sugar.

That has made it particularly interesting in metabolic health and diabetes research.

A 2023 systematic review and meta-analysis found that people with diabetes tended to have lower levels of several thiamine markers than people without diabetes, although the researchers emphasized that more work is needed to determine whether this translates into different supplementation requirements.

That doesn’t mean thiamine should be marketed as a blood-sugar treatment. And I’m definitely not saying it is, but it can help keep it in the heathy range.

A separate meta-analysis of supplementation trials found that thiamine and benfotiamine did not significantly improve fasting glucose or hemoglobin A1C in adults with type 2 diabetes over the relatively short periods studied.

So I wouldn’t use thiamine instead of proper diabetes treatment.

I would make sure someone isn’t deficient in a nutrient their cells need to process fuel normally.

So Who Should Take a Supplement of Thiamine? 

Let me start by saying only people who are deficient should look at targeted supplementation.

And from an integrative perspective I want to understand why thiamine became low in the first place.

• Is someone eating a very restricted diet? 

• Has there been prolonged nausea or vomiting?

• Heavy alcohol intake? 

• Bariatric surgery? 

• Malabsorption? 

• A medication or medical condition that increases risk?

Food should remain part of the solution too. Pork, legumes, whole and fortified grains, seeds and nuts can all provide thiamine.

For mild dietary inadequacy, improving food intake and appropriate oral supplementation may be enough. Severe deficiency…particularly when neurologic symptoms, persistent vomiting or significant malabsorption are involved can require urgent medical treatment and sometimes intravenous or injectable thiamine.

That isn’t something I’d try to manage with a standard supplement at home.

The good news is thiamine is inexpensive and for somebody who already has enough, taking huge amounts isn’t likely to unlock some hidden level of energy.

But when the body is genuinely running short, vitamin B1 becomes a very different story.

Restoring it can support energy production, protect normal neurologic function, maintain cardiovascular physiology and give metabolism one of the basic tools it needs to work properly.

Sometimes integrative medicine isn’t about finding the newest compound.

It’s about making sure the body has the essentials first.