Beriberi Disease: Vitamin B1 (Thiamine) Deficiency

Introduction

Beriberi is a serious and potentially life-threatening disease caused by a severe and prolonged deficiency of vitamin B1, also known as thiamine. Thiamine is an essential water-soluble vitamin that plays a fundamental role in energy metabolism, nerve function, and cardiovascular health. Without sufficient thiamine, the body cannot efficiently convert carbohydrates into energy, and critical organs such as the brain, nerves, and heart begin to malfunction.

The name “beriberi” originates from the Sinhalese language and means “I cannot, I cannot,” reflecting the profound weakness experienced by affected individuals. Although beriberi is uncommon in developed countries due to food fortification and improved nutrition, it remains a significant health problem in populations with malnutrition, chronic alcoholism, or certain medical conditions that impair nutrient absorption.

Beriberi can develop rapidly, sometimes within as little as two to three weeks of severely reduced thiamine intake, and if untreated, it can lead to permanent nerve damage, heart failure, and death.

Biological Role of Vitamin B1 (Thiamine)

Thiamine is essential for several critical biochemical processes, including:

1. Energy Production

Thiamine acts as a coenzyme in carbohydrate metabolism, particularly in the conversion of glucose into usable cellular energy (ATP). Organs with high energy demands, such as the brain and heart, are especially vulnerable to thiamine deficiency.

2. Nervous System Function

Thiamine is necessary for proper nerve signal transmission. It helps maintain the integrity of nerve cell membranes and supports neurotransmitter synthesis. Without adequate thiamine, nerve damage and neurological symptoms develop.

3. Cardiovascular Function

The heart requires continuous energy to pump blood effectively. Thiamine deficiency disrupts cardiac energy metabolism, leading to cardiac dysfunction, fluid accumulation, and heart failure.

4. Cellular and Mitochondrial Health

Thiamine supports mitochondrial function, which is essential for cellular respiration. Deficiency results in metabolic dysfunction, increased lactic acid production, and tissue damage.

Causes of Beriberi

Beriberi develops when thiamine intake is insufficient or when the body cannot properly absorb, store, or utilize the vitamin.

1. Dietary Deficiency

This is the most direct cause and commonly occurs in individuals whose diets consist mainly of:

Polished white rice
Refined grains
Highly processed carbohydrates
Foods lacking nutritional diversity

Polishing rice removes the outer bran layer, which contains most of the thiamine.

People at risk include:

Individuals with malnutrition
Those experiencing food insecurity
People consuming highly processed diets

2. Chronic Alcoholism

Alcohol use disorder is the leading cause of beriberi in developed countries.

Alcohol interferes with thiamine in several ways:

Reduces thiamine absorption in the intestines
Impairs thiamine storage in the liver
Increases thiamine excretion through urine
Reduces appetite and overall nutritional intake

Chronic alcohol use may also lead to severe neurological complications such as Wernicke-Korsakoff syndrome.

3. Medical Conditions Affecting Absorption

Several medical conditions impair thiamine absorption or increase loss, including:

Crohn’s disease
Chronic diarrhea
Persistent vomiting
Bariatric surgery
Dialysis
Gastrointestinal disorders

These conditions prevent proper nutrient absorption even when dietary intake appears adequate.

4. Increased Physiological Demand

Certain situations increase the body’s need for thiamine:

Pregnancy
Breastfeeding
Severe infections
Hyperthyroidism
Intense physical activity
Severe stress

If intake does not increase accordingly, deficiency can develop.

5. Infantile Beriberi

Infantile beriberi occurs in breastfed infants whose mothers are thiamine-deficient.

Infants are especially vulnerable because:

They have limited thiamine stores
They depend entirely on breast milk for nutrition

This form can lead to rapid heart failure and death if untreated.

Types of Beriberi

Beriberi is categorized into two main forms based on the organ systems affected.

Dry Beriberi (Neurological Form)

Dry beriberi primarily affects the nervous system.

Mechanism

Thiamine deficiency damages peripheral nerves, impairing signal transmission and causing progressive nerve degeneration.

Symptoms

Common neurological symptoms include:

Numbness in hands and feet
Tingling sensations (paresthesia)
Burning pain in extremities
Muscle weakness
Difficulty walking
Loss of coordination
Muscle wasting
Paralysis in severe cases

Early Neurological Signs

Early symptoms may include:

Fatigue
Irritability
Poor concentration
Memory problems
Sleep disturbances

Advanced Neurological Complications

Untreated deficiency can lead to:

Peripheral neuropathy
Loss of reflexes
Severe muscle atrophy
Permanent nerve damage

Wet Beriberi (Cardiovascular Form)

Wet beriberi primarily affects the cardiovascular system.

Mechanism

The heart cannot generate enough energy to pump blood effectively, resulting in circulatory failure.

Symptoms

Cardiovascular symptoms include:

Rapid heart rate (tachycardia)
Shortness of breath
Swelling in legs and feet (edema)
Fatigue
Chest discomfort
Enlarged heart

Severe Complications

In advanced cases, wet beriberi causes:

High-output heart failure
Fluid accumulation in lungs
Severe circulatory collapse
Death if untreated

Wet beriberi can progress rapidly and requires immediate medical intervention.

Wernicke-Korsakoff Syndrome

This is a severe neurological complication of thiamine deficiency, most commonly associated with chronic alcoholism.

It consists of two related disorders:

Wernicke Encephalopathy

This is an acute medical emergency characterized by:

Confusion
Loss of coordination (ataxia)
Abnormal eye movements
Double vision
Difficulty walking

Without treatment, it can progress to permanent brain damage.

Korsakoff Syndrome

This is a chronic and often irreversible condition involving:

Severe memory loss
Confabulation (creating false memories)
Personality changes
Cognitive impairment

Infantile Beriberi

Infantile beriberi develops in infants between 2 and 6 months old.

Symptoms include:

Rapid heart failure
Difficulty breathing
Vomiting
Restlessness
Loss of voice (aphonia)
Weak reflexes

This condition is life-threatening but treatable if recognized early.

Early Signs of Vitamin B1 Deficiency

Early symptoms may be subtle and include:

Fatigue
Weakness
Loss of appetite
Irritability
Abdominal discomfort
Poor concentration
Headaches

These symptoms often go unrecognized until more severe complications develop.

Advanced Signs of Thiamine Deficiency

As deficiency progresses, symptoms become more severe and may include:

Neurological symptoms:

Numbness
Tingling
Muscle weakness
Paralysis
Memory loss
Confusion
Difficulty walking

Cardiovascular symptoms:

Rapid heart rate
Swelling
Shortness of breath
Heart failure

Other symptoms:

Vertigo
Double vision
Loss of sensation
Severe fatigue

Risk Factors

Certain populations are at higher risk of developing beriberi.

Major risk groups include:

Chronic alcohol users
Malnourished individuals
People with restrictive diets
Individuals with gastrointestinal diseases
Dialysis patients
Post-bariatric surgery patients
Pregnant or breastfeeding women
Individuals with persistent vomiting
Elderly individuals
People with high carbohydrate diets lacking nutrient balance

Diagnosis

Diagnosis is based on:

Clinical symptoms and history:

Nutritional history
Alcohol use
Neurological examination
Cardiovascular assessment

Laboratory tests may include:

Blood thiamine levels
Blood lactate levels
Electrolyte testing

In many cases, treatment begins immediately if deficiency is suspected, even before laboratory confirmation.

Treatment

Beriberi is a medical emergency but is highly treatable if addressed early.

Immediate Treatment

Treatment involves thiamine replacement:

Intravenous thiamine injections for severe cases
Intramuscular injections if IV access is unavailable
Oral supplements for long-term treatment

Symptoms may begin improving within hours to days.

Recovery Timeline

Cardiac symptoms often improve rapidly
Neurological symptoms may take weeks or months
Severe nerve damage may be permanent if untreated too long

Prevention

Beriberi is preventable through proper nutrition.

Recommended daily intake:

Adult men: approximately 1.2 mg per day
Adult women: approximately 1.0–1.1 mg per day
Pregnant and breastfeeding women require slightly higher intake

Thiamine-rich foods include:

Whole grains:

Brown rice
Whole wheat
Oats

Protein sources:

Pork
Fish
Poultry
Eggs

Plant sources:

Beans
Lentils
Peas
Nuts

Fortified foods:

Cereals
Bread
Pasta

Balanced nutrition is the most effective preventive strategy.

Prognosis

The outcome depends on how quickly treatment begins.

If treated early:

Full recovery is possible
Heart damage is often reversible
Neurological symptoms may improve significantly

If untreated:

Permanent nerve damage
Heart failure
Brain damage
Death

Relationship Between Thiamine Deficiency and Bleeding Disorders

Thiamine deficiency does not directly cause von Willebrand disease or genetic clotting disorders. However, severe deficiency can create physiological stress that worsens bleeding tendencies.

Possible indirect effects include:

Increased metabolic stress
Weakening of capillary walls
Platelet dysfunction in severe illness
Increased vulnerability to hemorrhage

These effects may worsen symptoms in individuals with pre-existing bleeding disorders.

Global Health Significance

Beriberi remains a public health concern in regions where:

Diets rely heavily on polished rice
Malnutrition is prevalent
Food fortification is limited

Public health measures such as food fortification and nutritional education have significantly reduced incidence in developed nations.

Conclusion

Beriberi is a serious but preventable disease caused by vitamin B1 deficiency. Thiamine is essential for energy production, nerve function, and heart health. Deficiency leads to severe neurological and cardiovascular complications, including paralysis, heart failure, and brain damage.

The disease primarily affects individuals with poor nutrition, chronic alcoholism, malabsorption disorders, or increased physiological demands.

Early recognition and prompt thiamine replacement can reverse many symptoms and prevent permanent damage. Prevention through balanced nutrition and adequate vitamin intake remains the most effective strategy.

Beriberi serves as a critical reminder of the essential role of micronutrients in maintaining human health and the severe consequences that can arise from nutritional deficiency.