Vitamin B1 (Thiamine) 101: Benefits, Deficiency & Food Sources

A few years back, I found myself dragging through the day, barely making it past lunch without needing a nap. No matter how much I slept or how clean I ate, something was missing. Turns out, it wasn't just burnout—it was a lack of Vitamin B1, or thiamine.

If you've been dealing with fatigue, brain fog, nerve tingling, or mood swings, and especially if alcohol has played a role in your lifestyle, this might be the key nutrient your body is screaming for.

Let's explore why Vitamin B1 is one of the most critical, yet often overlooked, and life-changing nutrients for overall wellness.

• Vitamin B1 (Thiamine) is essential for energy production, brain function, and nerve health—but your body can’t store it, so daily intake is key.
  
  

• Alcohol use and withdrawal dramatically increase your risk of thiamine deficiency, which can lead to serious neurological conditions like Wernicke’s encephalopathy.
  
  

• Thiamine supplementation, especially high-dose or intravenous, can be life-saving during acute alcohol withdrawal or severe deficiency.
  
  

• Key sources of B1 include sunflower seeds, pork, brown rice, legumes, and fortified grains, but many people still fall short.
  
  

• Thiamine is often used in addiction recovery, critical care, and metabolic support, and should not be overlooked in nutritional or medical therapy.

Thiamine—often called Vitamin B1—is a water-soluble vitamin that helps your body convert food into energy. But it's more than just a metabolic helper. Thiamine fuels your nervous system, powers your heart, and keeps your brain sharp.

Inside the body, thiamine is converted into its active form, thiamine pyrophosphate (TPP), which is essential for intracellular glucose metabolism. Think of it as a key that unlocks the energy from your food, allowing your cells to thrive.

The body cannot store thiamine, so your intake must be consistent—either from food, dietary supplements, or therapeutic thiamine supplementation. According to dietary reference intakes established by nutrition authorities, maintaining adequate levels is essential for preventing deficiency states.

Mild or severe thiamin deficiency is more common than you think, especially if you're stressed, malnourished, or drink alcohol regularly. And yes, even if you only drink socially, it can still impact your thiamin metabolism.

Common Symptoms Include:

• Fatigue and weakness

• Brain fog and memory issues

• Mood disturbances

• Muscle cramps

• Tingling in the hands or feet (a sign of peripheral neuropathy)

• Poor coordination and balance

• Irritability or depression

In more extreme cases, untreated thiamine depletion can lead to Wernicke-Korsakoff syndrome, a serious neurological condition characterized by confusion, vision problems, and persistent memory issues, often seen in malnourished alcoholic patients or those with chronic alcohol use disorder.

Alcohol and thiamine have a complicated relationship. People experiencing acute alcoholic withdrawal symptoms are at high risk of thiamine deficiency disorders.

This is because alcohol interferes with:

• Thiamine transport across the intestinal wall

• Thiamine hydrochloride absorption

• Conversion to thiamin diphosphate

• Proper storage and use in the liver

Chronic drinkers often have low thiamine levels, which can worsen during periods of alcohol abstinence or acute alcohol withdrawal syndrome.

In fact, ethanol withdrawal syndrome is a well-documented cause of Wernicke's encephalopathy. This condition can arise within days of entering the alcoholic withdrawal phase, especially if oral or parenteral vitamins are not administered in time.

When your body runs dangerously low on thiamine, it can affect multiple systems:

Neurological Complications

• Confusion

• Memory loss

• Disorientation

• Coordination issues

• Alcohol-related cognitive disorders

Cardiovascular Risks

• Severe hypertension induced by autonomic dysfunction

• Acute cardiac failure in extreme thiamine deficiency (aka "wet beriberi")

Metabolic & Cellular Issues

• Severe metabolic acidosis

• Acute hyperkalemia induced by impaired renal function

• Abnormal thiamine-dependent processes in the brain and liver 

This is why thiamine administration is one of the first-line treatments in patients experiencing alcohol withdrawal seizures, acute ethanol poisoning, or a withdrawal syndrome scale score that indicates severe distress.

In clinical situations like acute spinal cord injury, acute alcohol withdrawal states, or acute pulmonary edema, patients often require oral or intravenous thiamine (or both).

IV Thiamine Is Often Used When:

• Malabsorption is present

• The patient is unconscious

• There's a need for rapid replenishment

• The patient has parenteral nutrition or is receiving adult parenteral multivitamins

Otherwise, for daily maintenance or recovery, oral thiamin supplementation (such as thiamine mononitrate) is usually sufficient, especially when paired with other B vitamins like pantothenic acid and folic acid.

You may need more B1 than the average person if you fall into any of these categories:

• Individuals with diabetes mellitus

• Those going through managing drug withdrawal syndromes

• People with chronic illnesses or severe inflammation

• Patients in addiction medicine working groups

• Those taking medications that impair thiamin status

• High-carb dieters (glucose metabolism requires more thiamine)

• Individuals with human vitamin status concerns due to a poor diet

• Patients undergoing nitrous oxide oxygen treatment, which can rapidly deplete B1 levels

In cases of deficiency, clinicians may use high dose thiamine protocols to restore levels. It's not uncommon to see thiamine supplementation at 100–500 mg/day in hospitalized patients to treat thiamine deficiency.

If you're not dealing with severe deficiency or medical conditions, you can maintain your population thiamine status through thiamine-rich foods, such as:

But let's be honest—not everyone eats well every day. And if you're recovering from alcohol withdrawal, battling malabsorption, or following drug treatment strategies, food alone may not cut it.

If you're shopping for supplemental thiamine, here's what to look for:

• Thiamin mononitrate: Most common, stable form

• Benfotiamine: A fat-soluble version for better bioavailability

• Thiamine pyrophosphate (TPP): Active form used in some high-end supplements

• Thiamine hydrochloride: Often found in IV solutions

Research into high thiamin intakes has shown promising results; however, more double-blind, placebo-controlled studies are needed to establish optimal therapeutic dosages for different conditions.

⚠️ Note: Don't self-prescribe megadoses. While rare, excess thiamine can cause allergic reactions or imbalances if taken without supervision.

As part of holistic healing in addiction medicine, B1 is often bundled into broader nutritional regimens aimed at restoring the human vitamin status. This includes oral thiamine supplementation, rehydration, folic acid, pantothenic acid, and other micronutrients.

It's also integrated into protocols for treating acute alcohol withdrawal syndrome or alcohol withdrawal states, where oral or intravenous thiamine is started alongside supportive therapies.

Whether you're a weekend wine lover, someone recovering from substance use, or just feeling tired and off your game, Vitamin B1 could be the quiet fix you need.

It's not just about energy. It's about nerve function, brain clarity, emotional stability, and long-term neurological protection.

Don't wait for your body to crash before giving it what it needs. Start with the basics—start with thiamine.

Feeling the signs? Talk to your doctor about checking your thiamin status, especially if you've been dealing with chronic fatigue, brain fog, or recent alcohol abstinence symptoms. Or consider adding a quality thiamine supplement to your wellness stack today.