What interferes with the absorption, intake, and use of thiamine?

October 22, 2025 •

4 min read

According to research, as many as 80% of individuals with chronic alcoholism may develop a thiamine deficiency, highlighting that what interferes with the absorption, intake, and use of thiamine can have severe health consequences. This essential vitamin, also known as B1, is critical for energy metabolism and proper nerve function, making it vital to understand the factors that can compromise its availability in the body.

Quick Summary

Several factors can compromise thiamine levels, including alcohol use disorder, malabsorption syndromes, chronic illnesses like diabetes and kidney disease, certain medications, and specific dietary elements such as thiaminases and antithiamine compounds. Genetics also play a role in some individuals.

Key Points

Alcoholism is a primary cause: Chronic alcohol use severely impairs thiamine absorption and utilization while increasing the body's need for the vitamin.
Thiaminases destroy thiamine: Enzymes in raw fish, shellfish, and specific plants can degrade thiamine, but cooking typically neutralizes them.
Antinutrients in beverages: Polyphenols in coffee, tea, and betel nuts are antithiamine factors that can inactivate the vitamin.
Certain medications deplete thiamine: Loop diuretics (e.g., furosemide) and chemotherapy drugs (e.g., fluorouracil) are known to increase thiamine loss or disrupt its metabolism.
Malabsorption and chronic illness pose risks: Conditions like gastric bypass surgery, celiac disease, chronic kidney disease, liver disease, and diabetes can all reduce thiamine availability.
Genetics can impede transport: Rare genetic mutations can affect thiamine transporters, causing disorders that lead to functional thiamine deficiency.

Thiamine, or vitamin B1, is a water-soluble vitamin essential for converting food into usable energy and maintaining healthy nerve function. Because the body stores only small amounts, a continuous dietary supply is necessary to prevent deficiency. While adequate intake is the first step, many factors can compromise absorption, increase metabolic demand, or destroy the vitamin before it can be utilized. Understanding these influences is crucial for maintaining optimal health.

Alcoholism: The Leading Cause of Thiamine Interference

Chronic alcohol use is one of the most common and significant causes of thiamine deficiency in developed countries. Alcohol interferes with thiamine in multiple ways:

Decreased Intake: Individuals with alcohol use disorder often consume less nutrient-dense food, leading to poor thiamine intake.
Impaired Absorption: Ethanol directly damages the gastrointestinal lining, reducing the active transport of thiamine across the intestinal wall.
Reduced Utilization and Storage: Alcohol impairs the liver's ability to store and activate thiamine, further compounding the issue.
Increased Requirement: The metabolic process of breaking down alcohol increases the body's need for thiamine.

These combined effects can lead to severe neurological conditions such as Wernicke-Korsakoff syndrome.

Dietary Components that Impact Thiamine

Certain foods contain compounds that can break down or inactivate thiamine, affecting its bioavailability.

Thiaminases in Raw Foods

Some raw or fermented foods contain thiaminase enzymes that destroy thiamine.

Raw freshwater fish and shellfish: Contain thiaminase I, which cleaves the thiamine molecule.
Bracken fern and other plants: Certain ferns and horsetail contain thiaminase, which is also a concern for livestock that graze on these plants.
Insects: The African silkworm, consumed in some cultures, contains a heat-resistant thiaminase that has been linked to neurological disorders.
Cooking as a Solution: For most sources, cooking effectively destroys thiaminase enzymes.

Antithiamine Factors

Polyphenolic compounds found in several common beverages and foods can also inactivate thiamine.

Coffee and Tea: The tannins and other polyphenols in coffee and black tea can degrade thiamine.
Betel Nuts: Consumption of betel nuts is another source of these antithiamine factors.
Protection from Ascorbic Acid: The presence of vitamin C (ascorbic acid) can help prevent this inactivation.

Other Nutritional Considerations

Refined Carbohydrates: Diets high in polished rice, white flour, and sugar provide calories without adequate thiamine, increasing the risk of deficiency.
Sulfites: Some food preservatives containing sulfites can destroy thiamine during processing.
Poor Cooking Practices: As a water-soluble vitamin, thiamine can leach into cooking water and be lost if the liquid is discarded.

Health Conditions and Medical Interventions

Various diseases and medical procedures can interfere with thiamine status, even with sufficient intake.

Malabsorption Syndromes: Conditions like celiac disease, Crohn's disease, and chronic diarrhea prevent proper intestinal absorption of thiamine.
Bariatric Surgery: Procedures such as gastric bypass can lead to severe thiamine deficiency due to malabsorption and restricted food intake.
Chronic Diseases: Liver disease impairs the metabolism and utilization of thiamine, while chronic kidney disease (especially with dialysis) increases its renal excretion. Diabetes is also linked to increased renal clearance of thiamine.
Increased Metabolic Demand: Pregnancy, lactation, hyperthyroidism, fever, and refeeding syndrome in malnourished patients all increase the body's need for thiamine, raising the risk of deficiency.

Medications and Genetic Factors

Drug Interactions

Loop Diuretics: Medications like furosemide, commonly prescribed for heart failure and edema, increase urinary output and lead to a significant loss of thiamine.
Chemotherapy Agents: The drug fluorouracil, used to treat certain cancers, can interfere with thiamine metabolism and block its active conversion.
Other Drugs: Some antibiotics and antivirals can also negatively impact thiamine levels.

Genetic Predisposition

Rare genetic disorders, such as Biotin-Thiamine-Responsive Basal Ganglia Disease (BTBGD), are caused by mutations in genes (e.g., SLC19A3) that encode for thiamine transporters. These mutations impair the cellular uptake and absorption of thiamine, leading to severe neurological symptoms that can be reversed with high-dose thiamine treatment if caught early.

Comparison of Factors Affecting Thiamine


Factor	Mechanism of Interference	Impact	At-Risk Groups
Alcoholism	Impaired absorption, decreased intake, reduced utilization	Severe deficiency (Wernicke-Korsakoff syndrome)	Individuals with chronic alcohol use disorder
Thiaminases	Enzymatic destruction of thiamine	Degradation of vitamin in raw food	Consumers of raw fish, shellfish, or certain ferns
Antithiamine Factors	Chemical inactivation by polyphenols	Reduced bioavailability of thiamine	Heavy drinkers of coffee or tea; betel nut chewers
Chronic Illness	Reduced absorption, increased loss, impaired utilization	Potential for long-term deficiency	Patients with liver disease, kidney disease, or diabetes
Malabsorption	Compromised intestinal function	Poor absorption despite adequate intake	Post-bariatric surgery, Crohn's, celiac disease patients
Medications	Increased excretion, disrupted metabolism	Increased risk of deficiency	Long-term diuretic or specific chemotherapy users
Genetics	Impaired cellular transport	Inborn error of metabolism affecting thiamine use	Individuals with rare genetic mutations (e.g., SLC19A3)

Conclusion: Navigating Thiamine Risks for Optimal Health

While severe thiamine deficiency leading to conditions like beriberi is less common today due to fortified foods, a significant number of individuals remain at risk due to various interfering factors. The complexity of what interferes with the absorption, intake, and use of thiamine involves more than just diet, encompassing chronic disease, lifestyle choices like alcohol consumption, specific medications, and even genetics. For at-risk populations, being aware of these factors is the first step toward prevention. A balanced diet, careful consideration of medication side effects, and open communication with healthcare providers about potential risks are all vital to ensure adequate thiamine status and avoid potential health complications.

National Institutes of Health (NIH) - Thiamin Fact Sheet

Frequently Asked Questions

Chronic alcohol consumption is a major cause of thiamine deficiency because it reduces dietary intake, impairs absorption through the intestinal wall, and decreases the liver's ability to store and activate the vitamin.

Thiaminases are enzymes that destroy thiamine. They are found in raw or fermented fish and shellfish (like clams and mussels), as well as in some plants such as bracken fern. Cooking foods that contain thiaminases typically inactivates them.

Yes, coffee and tea contain polyphenolic compounds that are considered antithiamine factors. These compounds can degrade or inactivate thiamine, especially in high-volume consumption.

Conditions that increase metabolic demand, impair absorption, or cause excessive loss can increase risk. This includes hyperthyroidism, liver disease, chronic diarrhea, diabetes, chronic kidney disease, and malabsorption syndromes.

Yes, bariatric surgeries like gastric bypass can lead to severe thiamine deficiency. This is due to a combination of reduced food intake and significant malabsorption caused by changes to the gastrointestinal tract.

Some medications are known to interfere with thiamine. Loop diuretics, such as furosemide, can increase urinary excretion of thiamine. Certain chemotherapy agents, like fluorouracil, can also disrupt thiamine metabolism.

Yes, rare genetic mutations affecting thiamine transporter proteins can impair the body's ability to transport and utilize the vitamin. These can lead to inherited disorders that present as thiamine deficiency.