Beriberi is a condition that results when the body has a chronic shortage of thiamine (vitamin B1). Thiamine is necessary for digestion, metabolism and communication between nerves and muscles. Nutritionally, it is available from many foods, including lean meats, beans and whole grains. Enriched foods contain extra vitamins and thiamine is often among the additions.

In the United States and other Western, industrialized nations, dietary thiamine deficiency is rare. Many cases occur in conjunction with alcohol abuse, because alcohol reduces the body’s ability to absorb thiamine and increases its elimination from the body. Other occurrences of the disease may be related to medical treatments or conditions that limit the body’s ability to utilize the vitamin.

Early symptoms and signs of beriberi include fatigue, depression and loss of appetite. There are two general forms of beriberi: “wet” and “dry.” Wet beriberi impacts cardiovascular function and leads to swelling of the legs, fluid in the lungs, and rapid heart rate. Dry beriberi affects the nerves and muscles, causing memory loss and mental confusion, pain in the hands and feet, involuntary eye movements, and trouble moving and standing. In most cases, symptoms of wet and dry beriberi overlap, and prolonged thiamine deficiency may result in paralysis, heart failure and death.

To diagnose beriberi, the physician may assess the patient’s symptoms in response to a dose of the vitamin and measure the amount of thiamine in blood or urine. Initial treatment requires thiamine supplementation through injection or intravenous (I.V.) fluids. Following the first stages of recovery, thiamine supplements pills are often used. Recovery from some symptoms is often rapid. However, depending on severity, some of the disease’s effects (e.g., memory loss) may not be completely reversible.

Beriberi can largely be prevented by consuming a diet containing the recommended amounts of thiamine. Adults require between 1.1 and 1.4 milligrams per day (mg/d) according to the Food and Nutrition Board of the National Academy of Sciences. People at greatest risk of not consuming sufficient thiamine should consult their physicians. This group includes pregnant or nursing mothers, patients undergoing dialysis treatments or taking diuretic drugs and abusers of alcohol.

Beriberi is a condition that occurs when the body does not receive enough thiamine (vitamin B1) over a prolonged period of time. Translated from Sri Lankan, beriberi means “I can’t, I can’t,” reflecting the often incapacitating nature of this condition.

This condition led to the discovery of thiamine in the 1920s. Scientists researching the cause of beriberi identified thiamine as a water-soluble vitamin essential for many of the body’s systems. It is found on the myelin sheath of nerve cells, a vital part of the cell that helps conduct nerve signals between cells and muscles. Each cell depends on thiamine as part of thiamin pyrophosphate, an enzyme involved in metabolism. Thiamine also plays a role in the production of hydrochloric acid in the stomach, making chemical digestion of food possible. Without thiamine, the body is unable to function.

Unlike vitamins stored in fat tissues, water-soluble vitamins like thiamine quickly pass through the body. Without the proper dietary intake, thiamine deficiency can occur within 14 days to a month. In children, insufficient thiamine may result in learning difficulties later in life. Chronic deficiency at any age may affect the heart, muscles, gastrointestinal or nervous systems, leading to serious health implications. If untreated, beriberi can be fatal.

While the entire body is likely to be impacted, beriberi is classified by the body system most affected: either the cardiovascular or nervous and muscular systems. The patient’s diet and activity level are the primary determining factors for which type develops, although some overlap can occur. These primary types are:

• Wet beriberi. Impacts the cardiovascular system. This type tends to occur in patients with high caloric intake and active lifestyles. It is characterized by fluid retention within the body and damage to the heart. One type of wet beriberi, Shoshin beriberi or acute fulminant cardiovascular beriberi, results from a rapid, initial injury to the heart and proceeds much faster than typical wet beriberi.
  
  
• Dry beriberi. impacts the nervous and muscular systems. Patients with low caloric intake and sedentary lifestyles are more likely to develop this type. It generally includes difficulties in movement and impaired mental function. When the disease impacts the brain or central nervous system, it may be further classified as cerebral beriberi or Wernicke Korsakoff Syndrome.

Beriberi may be further described by the population affected or the cause of thiamine deficiency causing the conditions. Examples include:

• Infantile beriberi. This typically appears in children younger than four months and is associated with a high mortality rate unless diagnosed and treated promptly. It may be caused by breastfeeding mothers who are themselves thiamine deficient or formula-feeding infants with a formula without the proper balance of nutrients.
  
  
• Genetic beriberi. An inherited medical condition in which the body cannot absorb thiamine from food. Example of genetic beriberi may include subacute necrotizing encephalopathy (SNE), maple syrup urine disease and lactic acidosis.

Beriberi can result from a variety of factors that affect the amount of thiamine (vitamin B1) in the body, including behaviors or other medical conditions. It occurs as the result of prolonged thiamine deficiency, but dietary intake is rarely the only factor causing deficiency in Western nations.

Most cases of beriberi in the United States are related to alcohol abuse. Alcohol creates chemical barriers that reduce the ability of tissues and cells to absorb and utilize thiamine. Alcohol also increases the rate the body excretes thiamine, further preventing its absorption. Compounding this, alcoholics often substitute alcohol for food and therefore consume insufficient nutrients, including thiamine. Furthermore, some studies have suggested that a combination of alcoholism and beriberi may cause more seious symptoms than the sum of the two conditions.

In addition to alcohol, other factors increase the risk of inadequate thiamine intake, including:

• Eating disorders. Patients who suffer from eating disorders are also likely to be malnourished with little to no thiamine intake.
  
  
• Processed diets. People whose diets consisting largely of white rice or highly processed foods may not receive sufficient thiamine. Thiamine is often removed during processing.
  
  
• Breast or formula-feeding. Infants breast-fed by malnourished mothers or given formula without proper vitamins may not receive enough thiamine resulting in infantile beriberi.
  
  
• Chronic vomiting, appetite loss or diarrhea. Any medical treatment or condition that causes these symptoms can potentially result in malnourishment and thiamine deficiency.
  
  
• Intestinal surgeries. Certain intestinal procedures (e.g., gastric bypass surgery) have been known to contribute to malnutrition.

Some factors impact the body’s ability to absorb or use thiamine. When compounded with other causes they may lead to beriberi. These include:

• Dialysis. Treatments to remove waste products from the blood of patients with kidney failure. They may also remove thiamine before the body can use it.
  
  
• Diuretics. Medications that increase urine output. These have the potential to decrease the amount of time certain nutrients, including thiamine, are in the body and available for use.
  
  
• Genetic disorders. In some cases, genetic conditions prevent the body from absorbing thiamine from food.
  
  
• Certain foods, such as coffee, tea, and raw shellfish and freshwater fish. These foods contain chemicals that destroy thiamine before it can be used by the body. However, they must be consumed in extremely large amounts to cause thiamine deficiency.

Certain conditions increase the body’s need for thiamine and failing to ingest the increased amount can lead to beriberi. These factors include:

• Pregnancy and breastfeeding. Pregnant or breastfeeding mothers require more thiamine than other women of their age group.
  
  
• Hyperthyroidism (overactive thyroid). Having too much thyroid hormone in the body causes nutrients to metabolize more quickly, including thiamine. Therefore, greater amounts are needed than in the typical diet.
  
  
• Severe diseases. Conditions that cause the body to consume large amounts of energy result in a need for additional thiamine. Examples of these conditions include malaria, cancer, severe liver disease and HIV infection.
  
  
• Intravenous feeding (total parenteral nutrition [TPN]). Patients receiving intravenous feeding for more than 7 days without a multivitamin or dietary thiamin are at an increased risk for thiamine deficiency.

Beriberi results from prolonged and chronic deficiency of thiamine (vitamin B1), but early signs and symptoms of thiamine deficiency may be detected in 14 days, before the onset of more severe symptoms. These are consistent with other vitamin deficiencies and may include:

• Fatigue
• Apathy
• Irritability
• Depression
• Poor mental concentration and memory loss
• Lack of appetite
• Sleep disturbances
• Nausea
• Abdominal discomfort
• Weight loss
• Hoarseness

Thiamine deficiency progresses to beriberi when left untreated, causing more severe signs and symptoms. These develop after approximately three months of insufficient vitamin consumption and vary depending on which form the disease takes. The signs and symptoms of wet beriberi (affecting the cardiovascular system) may include:

• Rapid heart rate
• Dilation of blood vessels
• Warm, moist skin
• Fluid in the lungs
• Heart enlargement and eventually failure
• Swelling of extremities due to fluid build up (edema), especially in the legs
• Shortness of breath with activity
• Awakening at night with shortness of breath

Dry beriberi (affecting the nervous and muscular systems) is not characterized by swelling and fluid accumulation, hence the term “dry.” Instead, signs and symptoms involve the senses, memory and movement. Dry beriberi can lead to coma and death. Symptoms may include:

• Pain, tingling or numbness in hands and feet
• Decreased or exaggerated reflexes
• Inability to sense vibrations
• Vomiting
• Involuntary, cyclical eye movements (nystagmus)
• Vision changes
• Difficulty standing or walking
• Language difficulties
• Drooping eyelids
• Seizures
• Muscle wasting, leading to loss of function or paralysis of the legs and arms 
• Mental confusion 

In infants, the signs and symptoms of beriberi may develop after two to three months. They may include:

• Enlargement of the heart
• Rapid heart rate
• Loud, piercing crying
• Bluish discoloration of the skin, lips and nails
• Difficulty breathing
• Vomiting

Diagnosis of beriberi usually involves a medical history and physical examination. The medical history may include questions on the duration, severity and progression of symptoms, diet, other medical conditions present and alcohol use. The physical examination may include looking for signs of beriberi of which the patient may not be aware, including swollen legs, fluid in the lungs and a rapid heartbeat. A neurologic examination may detect loss of vibratory sensation, poor or exaggerated reflexes, loss of coordination, cyclical eye movements or other indicators.

If beriberi is suspected, physician may perform one or more of the following tests:

• Thiamine dose test. The patient is given a dose of thiamine and symptoms are monitored. If the patient’s condition improves within 12 to 24 hours, beriberi is diagnosed and treatment commences.
  
  
• Blood test. Samples may be taken from the patient to assess the amount of thiamine in the blood. This may be achieved by directly measuring the amount of thiamine using high-performance liquid chromatography (HPLC) or by comparing the activity of blood enzymes before and after thiamine is added.
  
  
• Thiamine urine test. This test measures the amount of thiamine or its metabolites excreted in the urine.

Physicians treat beriberi by increasing the amount of thiamine (vitamin B1) in the patient’s body. Initial doses may be given intravenously (I.V.) or injected over seven days. Following that, thiamine is usually given as a pill until recovery is complete, usually several weeks. Additional supplements may be given to treat other diseases related to vitamin deficiency. When a breast-fed infant develops beriberi, both the mother and child will receive treatment to address the deficiency.

With treatment, symptoms may show rapid improvement in the first 12 hours. Most neurological symptoms are completely reversed and heart function normalizes in the first few days. Treatment will continue over several weeks, even after symptoms disappear. Over time, heart swelling and further damage can be controlled and may also be reversed. Memory problems may take months to respond and, depending on severity, recovery may be incomplete. Lack of treatment may result in permanent neurological damage or death.

Consuming a diet with sufficient amounts of thiamine (vitamin B1) prevents most cases of beriberi. Recommendations for intake are made by the Food and Nutrition Board of the National Academy of Sciences.

To meet these recommendations, the best dietary sources of thiamine are:

• Fish and lean meats, especially pork
• Enriched breads and cereals
• Whole grain products, especially wheat germ
• Fresh fruits and vegetables (if consumed in large amounts)
• Legumes (e.g., peas, beans, soybean)

Food preparation is also important since the vitamin can be destroyed by overcooking and may dissolve in water during boiling.

Nursing mothers should consume sufficient thiamine for themselves as well as their infants. When providing formula to the infant, the parent should check its nutritional information to ensure that it contains recommended levels of thiamine. As infants move from breast milk and formula to other foods, their diet should include thiamine-rich foods, such as whole grains, fresh fruits and vegetables.

Preparing questions in advance can help patients to have more meaningful discussions regarding their conditions. Patients may wish to ask their doctor the following questions related to beriberi:

1. Am I at risk for beriberi?
   
   
2. What can I do to prevent the occurrence or recurrence of beriberi for me and my family?
   
   
3. Should I consult a registered dietitian regarding dietary changes or nutritional supplements to reduce my risk?
   
   
4. What early signs and symptoms should I be on the lookout for?
   
   
5. Do I have wet beriberi or dry beriberi? What is the difference?
   
   
6. What treatment options do you recommend for me?
   
   
7. Is it possible for me to take too much thiamine?
   
   
8. How quickly will treatment take effect and how complete will my recovery be?
   
   
9. I have one or two glasses of beer or wine a week, should I be concerned about beriberi?
   
   
10. Am I at risk for other diseases related to vitamin deficiency?