What are the disorders of vitamin B1 thiamine deficiency?

December 27, 2025 •

3 min read

According to the National Institute on Alcohol Abuse and Alcoholism, Wernicke-Korsakoff syndrome, a major disorder of vitamin B1 thiamine deficiency, affects up to 2% of people worldwide. This essential vitamin is crucial for energy metabolism and nervous system function, and its deficiency can lead to severe and life-threatening conditions.

Quick Summary

This article details the disorders caused by a lack of vitamin B1, including wet and dry beriberi, Wernicke-Korsakoff syndrome, and infantile beriberi. It covers neurological and cardiovascular impacts, risk factors like alcohol use and malnutrition, and the importance of timely diagnosis and treatment.

Key Points

Beriberi is a severe form of thiamine deficiency: It can be categorized into wet (cardiovascular) and dry (neurological) forms, affecting different body systems.
Wernicke-Korsakoff Syndrome is a brain disorder: This two-stage condition involves acute Wernicke's encephalopathy leading to chronic Korsakoff's psychosis with severe memory loss.
Chronic alcoholism is a primary risk factor: Alcohol abuse interferes with thiamine absorption, storage, and utilization, significantly increasing the risk of deficiency.
Early symptoms are often vague: Initial signs like fatigue, irritability, and loss of appetite can be overlooked, delaying diagnosis.
Diagnosis is often based on response to treatment: A favorable clinical response to thiamine supplementation can help confirm the diagnosis, especially when other tests are limited.
Prompt treatment is critical for recovery: Early and high-dose thiamine treatment can reverse many symptoms and prevent permanent neurological damage.

Understanding Thiamine Deficiency

Thiamine, also known as vitamin B1, is a vital water-soluble vitamin essential for cellular metabolism and converting carbohydrates into energy. As the body cannot produce thiamine, dietary intake or supplementation is necessary. A lack of thiamine can disrupt nervous and cardiovascular functions, leading to serious disorders like beriberi and Wernicke-Korsakoff syndrome.

The Spectrum of Thiamine Deficiency Disorders

Severe thiamine deficiency results in beriberi, classified by the affected system.

Wet Beriberi

Wet beriberi primarily affects the cardiovascular system, causing high-output congestive heart failure and peripheral vasodilation. Symptoms include a rapid heart rate, shortness of breath, and edema in the lower limbs. Untreated, it can lead to fatal heart failure. A rare, acute form called Shoshin beriberi can cause rapid cardiovascular collapse.

Dry Beriberi

Dry beriberi impacts the nervous system, resulting in peripheral neuropathy and muscle wasting. Symptoms include pain, tingling, numbness, muscle weakness, atrophy, and diminished reflexes. Severe cases can cause difficulty walking and partial paralysis.

Gastrointestinal and Infantile Beriberi

Gastrointestinal beriberi presents with abdominal pain, nausea, vomiting, and lactic acidosis. Infantile beriberi is a critical condition in infants breastfed by deficient mothers, potentially causing sudden heart failure.

Wernicke-Korsakoff Syndrome (WKS)

WKS is a severe neurological disorder from chronic thiamine deficiency, often linked to chronic alcohol use.

Wernicke's Encephalopathy

This acute, often emergency phase includes confusion, eye movement problems, and difficulty with coordination. Eye issues may be reversible with prompt treatment.

Korsakoff's Psychosis

The chronic stage following untreated Wernicke's, characterized by severe short-term memory loss, confabulation, and inability to form new memories. Memory impairment is often permanent.

Comparison of Major Thiamine Deficiency Disorders


Feature	Wet Beriberi	Dry Beriberi	Wernicke-Korsakoff Syndrome
Primary System Affected	Cardiovascular	Nervous System (Peripheral)	Nervous System (Central)
Key Symptoms	Shortness of breath, rapid heart rate, edema, heart failure	Tingling/numbness, muscle weakness, atrophy, pain	Confusion, ataxia, eye movement issues, severe memory loss, confabulation
Onset	Can be acute or chronic, with rapid progression in severe cases	Gradual onset, starting with peripheral neuropathy	Acute (Wernicke's) followed by chronic (Korsakoff's) if untreated
Causes	Severe nutritional deficiency, high-carbohydrate intake	Severe nutritional deficiency, often with low caloric intake	Chronic alcoholism, malabsorption disorders
Reversibility	Highly reversible with prompt treatment, especially cardiovascular symptoms	Can be reversed, but some nerve damage may be permanent	Wernicke's symptoms can be partially reversed; Korsakoff's memory damage is often permanent

Causes and Risk Factors

Thiamine deficiency stems from issues with intake, absorption, or increased needs.

Chronic Alcohol Use Disorder: Common cause in industrialized countries, as alcohol hinders thiamine processing.
Malnutrition and Poor Diet: Insufficient intake of thiamine-rich foods, especially diets high in polished white rice.
Gastrointestinal Issues: Conditions like chronic diarrhea, malabsorption syndromes, and post-bariatric surgery can impede absorption.
Increased Need: Pregnancy, breastfeeding, hyperthyroidism, and prolonged fever increase thiamine requirements.
Certain Medical Treatments: Long-term diuretic use can increase thiamine excretion.

Diagnosis and Treatment

Diagnosis

Diagnosis often relies on clinical signs, risk factors, and response to thiamine treatment due to limited specific tests. Blood tests can measure thiamine, and MRIs can show WKS brain damage.

Treatment

Treatment primarily involves thiamine supplements.

Supplementation: Given orally, or intravenously/intramuscularly for severe cases or WKS.
Addressing Underlying Cause: Essential to treat the root cause, such as stopping alcohol or improving diet.
Supportive Care: May be needed for heart issues in wet beriberi.

Conclusion

Vitamin B1 thiamine deficiency causes severe disorders affecting the nervous and cardiovascular systems. Beriberi and Wernicke-Korsakoff syndrome underscore thiamine's vital role. Timely symptom recognition and prompt thiamine treatment are crucial for better outcomes and preventing irreversible damage, particularly in high-risk groups like those with chronic alcoholism or malnutrition. A balanced diet rich in thiamine is the best prevention.

For more information on the clinical aspects and treatment guidelines for thiamine deficiency, consult reputable medical resources like the NCBI Bookshelf.

Frequently Asked Questions

The main causes include chronic alcoholism, malnutrition from poor diet (especially polished white rice or processed carbs), malabsorption issues, and increased bodily needs during pregnancy or hyperthyroidism.

Wet beriberi primarily affects the cardiovascular system, causing symptoms like rapid heart rate, fluid retention, and heart failure. Dry beriberi mainly impacts the nervous system, leading to nerve damage, muscle weakness, and numbness.

The acute stage, Wernicke's encephalopathy, can often be reversed with prompt, high-dose thiamine treatment. However, the chronic stage, Korsakoff's psychosis, which involves severe memory loss, is often permanent.

Early symptoms can be nonspecific and include fatigue, irritability, poor memory, loss of appetite, and sleep disturbances. These can be easily mistaken for other conditions.

Treatment involves thiamine supplementation, given either orally or intravenously depending on the severity of the deficiency. It is crucial to also address the underlying cause, such as alcoholism or diet.

High-risk groups include individuals with chronic alcohol use disorder, those with malabsorption syndromes (e.g., post-bariatric surgery), people with eating disorders, and those on long-term diuretics.

Yes, particularly in the form of Korsakoff's psychosis, which causes severe and sometimes permanent memory loss. Even in milder cases, poor short-term memory can be a symptom.