What are the deficiency disease and symptoms of vitamin B1?

November 16, 2025 •

3 min read

An estimated 80% of individuals with chronic alcohol use disorder develop a thiamine deficiency, which can cause significant health problems. Understanding what are the deficiency disease and symptoms of vitamin B1 is crucial, as this essential nutrient affects energy metabolism, nerve function, and cardiovascular health.

Quick Summary

A deficiency in vitamin B1 (thiamine) leads to conditions like beriberi and Wernicke-Korsakoff syndrome, causing neurological and cardiovascular issues. Poor diet, alcoholism, malabsorption, and other medical conditions are key causes.

Key Points

Thiamine Deficiency: The condition is known as beriberi, with severe forms also impacting the brain, such as Wernicke-Korsakoff syndrome.
Dry Beriberi: Affects the nervous system, causing symptoms like peripheral neuropathy (numbness, tingling), muscle weakness, and impaired reflexes.
Wet Beriberi: Impacts the cardiovascular system, leading to fluid retention (edema), rapid heart rate, and potentially heart failure.
Wernicke-Korsakoff Syndrome: A severe neurological disorder associated with chronic alcoholism, causing confusion, memory loss, and eye movement abnormalities.
Risk Factors: High-risk groups include individuals with chronic alcoholism, bariatric surgery patients, pregnant or breastfeeding women, and those on certain medications.
Treatment: Involves thiamine supplementation, given orally or intravenously depending on the severity, along with dietary improvements.

Understanding Thiamine and its Critical Role

Thiamine, also known as vitamin B1, is a water-soluble vitamin essential for converting food into energy, especially carbohydrates. It plays a crucial role in nerve, muscle, and heart function and has a relatively short storage time in the body, meaning a consistent dietary intake is necessary. A persistent lack of thiamine can lead to severe health consequences, with the most well-known deficiency disease being beriberi.

The Forms and Symptoms of Beriberi

Beriberi is a severe vitamin B1 deficiency that primarily impacts the nervous and cardiovascular systems. It manifests in different forms with distinct symptoms, historically affecting populations reliant on polished rice.

Dry Beriberi: Affecting the Nervous System

This form causes nerve and muscle abnormalities. Symptoms often begin in the extremities and can include peripheral neuropathy, muscle weakness, and difficulty walking.

Wet Beriberi: Impacting the Cardiovascular System

Wet beriberi affects the heart and circulatory system and can be life-threatening if not treated quickly. Symptoms include rapid heartbeat, swelling, and heart failure.

Infantile Beriberi

This occurs in infants breastfed by thiamine-deficient mothers.

Wernicke-Korsakoff Syndrome: Thiamine Deficiency and Brain Damage

Severe thiamine deficiency can lead to brain abnormalities, particularly in those with chronic alcohol use disorder. This condition has two components:

Wernicke Encephalopathy: This acute phase causes confusion, apathy, difficulty walking (ataxia), and eye problems like involuntary eye movements (nystagmus). It is a medical emergency.
Korsakoff Psychosis: Untreated Wernicke encephalopathy can progress to Korsakoff psychosis, involving severe short-term memory loss, confusion, and confabulation.

Common Causes and Risk Factors

Thiamine deficiency can result from poor dietary intake (especially diets high in polished white rice or processed carbohydrates), chronic alcohol use, medical conditions (like bariatric surgery, malabsorption syndromes, kidney disease, HIV/AIDS), increased needs (during pregnancy, breastfeeding, hyperthyroidism), certain medications, and consuming foods containing anti-thiamine factors like raw fish.

Diagnosis and Treatment

Diagnosis involves a physical exam, medical history, and blood tests. Treatment involves thiamine supplementation, given orally or intravenously depending on severity, along with dietary adjustments and addressing underlying conditions.

Prevention is Key

Preventing thiamine deficiency is more effective than treating it, primarily through a varied diet and fortified foods. For those at risk, supplementation and managing underlying health issues are crucial.


Feature	Deficiency in Developed Nations	Deficiency in Developing Nations
Primary Cause	Chronic alcohol use disorder, bariatric surgery, malabsorption syndromes.	Poor dietary intake, diets high in polished rice, food insecurity.
Associated Condition	Wernicke-Korsakoff syndrome is a primary concern.	Beriberi, especially wet or dry beriberi, is more common.
Typical Presentation	Often a mix of neurological and psychiatric symptoms, sometimes without classic beriberi signs.	More classic presentations of dry (neurological) or wet (cardiac) beriberi symptoms.
Treatment Challenges	Non-compliance with treatment for underlying issues (e.g., alcoholism).	Access to fortified foods and supplements can be limited.

Conclusion

Thiamine deficiency is a serious condition with potential neurological (dry beriberi) and cardiovascular (wet beriberi) impacts, as well as cognitive impairment (Wernicke-Korsakoff syndrome). Early diagnosis and treatment are vital. Prevention is best through a balanced diet, supplementation for those at risk, and managing underlying health issues. For more information, consult resources like the {Link: National Institutes of Health https://ods.od.nih.gov/factsheets/Thiamin-HealthProfessional/}.

Foods Rich in Thiamine (Vitamin B1)

Good sources include pork, fortified cereals, legumes, nuts, and whole grains.

Frequently Asked Questions

The primary deficiency disease of vitamin B1 (thiamine) is called beriberi. Severe or chronic deficiency can also lead to a neurological disorder known as Wernicke-Korsakoff syndrome.

Early symptoms are often vague and can include fatigue, irritability, loss of appetite, poor memory, nausea, and vomiting. These can be easily overlooked or mistaken for other conditions.

A severe vitamin B1 deficiency, known as wet beriberi, can lead to cardiovascular problems. Symptoms include a rapid heartbeat, shortness of breath, fluid buildup (edema) in the legs and lungs, and eventually, heart failure.

Wernicke-Korsakoff syndrome is a severe brain disorder caused by thiamine deficiency, most commonly associated with chronic alcoholism. It causes confusion, memory loss, balance issues, and visual disturbances.

People with chronic alcohol use disorder, those who have undergone bariatric surgery, individuals with malabsorption disorders, and those with poor dietary intake are at higher risk. Increased metabolic needs during pregnancy can also raise the risk.

Diagnosis typically involves a physical examination and reviewing the patient's history and symptoms. Blood tests, such as measuring the activity of the enzyme transketolase, can help confirm the deficiency.

Good sources of thiamine include pork, fish, whole and enriched grains (like brown rice and fortified cereals), nuts (sunflower seeds, macadamia nuts), and legumes (black beans, lentils).