Beriberi is the result of a thiamine deficiency; thiamine is also known as vitamin B1. The condition is rare in the United States due to the availability of vitamin-enriched foods. If left untreated, beriberi can be life-threatening.
Definition & Facts
Beriberi is most often seen in regions where the diet consists mostly of unenriched white rice or cassava flour. Beriberi is classified as either wet or dry. Wet beriberi targets the heart and circulatory system and can lead to heart failure in extreme cases. The dry form of beriberi affects the central nervous system and can lead to a decrease in muscle strength and even paralysis.
Severe cases of beriberi are associated with two forms of brain damage known as Korsakoff's syndrome and Wernicke's encephalopathy. Korsakoff syndrome can lead to memory loss, an inability to retain new memories, and even hallucinations. Wernicke's encephalopathy damages the thymus and hypothalamus portions of the brain. This can result in memory loss, confusion, visual problems, and poor muscle coordination.
Symptoms & Complaints
The symptoms of dry beriberi are neurological in nature. The patient may experience pain, tingling, or loss of sensation in their hands and feet. They may also have a loss of muscle function and even paralysis in their legs.
The patient may demonstrate mental confusion, have difficulty speaking, and unusual eye movements called nystagmus. Some patients also experience nausea and vomiting. The symptoms of both wet and dry beriberi may be continuous or intermittent.
Many of the symptoms are reversible provided the patient seeks prompt medical treatment. If untreated, beriberi symptoms can become permanent and pose a risk of serious complications, including:
- Chronic pain
- Loss of mobility
- Congestive heart failure
- Permanent neurological problems
- Psychotic episodes
Vitamin B1 is a water-soluble vitamin. The vitamin is absorbed through dietary sources and is stored in muscles and various organs. A person develops beriberi when they do not ingest enough thiamine, or they are unable to absorb and utilize it effectively.
In the United States, most cases of beriberi occur in patients who regularly abuse alcohol. Chronic alcohol abuse or alcohol use disorder is often associated with poor nutrition. Alcohol also inhibits the body’s ability to absorb and store vitamin B1.
In rare cases, a form of inherited beriberi can develop over time and present with symptoms during adulthood as the body slowly loses the ability to absorb thiamine from dietary sources. This form of the disease is often overlooked since most health care providers only associate beriberi with alcoholism.
Kidney dialysis, prolonged diarrhea, and the use of diuretics can deplete the body’s stores of thiamine. Infants may also develop the condition if they drink formula that is low in thiamine or if the nursing mother does not get enough thiamine in her diet.
Diagnosis & Tests
A patient’s physical and neurological symptoms will typically lead a doctor to suspect that a patient has thiamine deficiency. Depending on the type of beriberi, a diagnostic exam will show signs of congestive heart failure or neurological deficits. If the condition is advanced, the patient may also have an altered mental status, including delusions and memory loss.
If the doctor suspects that a patient’s symptoms may be the result of beriberi, they may simply treat the patient with thiamine as a way of testing for the disease. Since thiamine is not toxic in large doses in individuals with normal kidney function, this is a safe, quick, and inexpensive way to confirm the diagnosis. The patient also gets the benefit of faster treatment. The drawback to this approach is that it does not necessarily catch subclinical forms of beriberi.
If more definitive testing is required, the doctor may order blood tests and clinical urine tests to measure the level of thiamine in the body. A patient having trouble absorbing thiamine will typically have decreased serum levels of the vitamin and increased levels in the urine.
Treatment & Therapy
Treatment is aimed at replacing the vitamin B1 that the patient is lacking. In most cases, thiamine will be administered orally through supplements or by injection. The therapy is typically continued until the patient’s symptoms resolve. Depending on the underlying cause of the deficiency, a maintenance regimen of supplemental thiamine and other vitamins may be recommended. If the beriberi is the result of alcoholism, the patient may require a referral to an inpatient or outpatient alcohol dependency clinic or program.
The patient should undergo routine follow-up as directed by their doctor. Follow-up typically includes repeat laboratory tests to ensure that the patient’s thiamine levels are within normal range. Additional testing may also be required if the doctor suspects relapse or that the patient is non-compliant with their treatment regimen.
Patients with pregnancy-related beriberi should work closely with their physician until delivery. Patients suffering from heart failure resulting from wet beriberi may require hospitalization and additional cardiac support until their heart function improves.
Prevention & Prophylaxis
- Beans and legumes
- Fresh vegetables
- Whole grains
Most of today’s breakfast cereals are fortified with vitamin B1 and contain 100 percent of the recommended daily requirement of thiamine. Pregnant women and nursing mothers should be checked regularly for vitamin deficiencies and take supplements as advised by their doctor.
Most prenatal vitamins do contain B-complex vitamins, including thiamine. Parents using infant formulas should ensure that they choose a formula that contains plenty of thiamine.
Anyone who habitually abuses alcohol is at significant risk of developing beriberi in addition to numerous other health conditions. These individuals should seek substance abuse counseling and support in order to quit. They should also be open with their health care provider about their abuse so that they can be checked and treated for any thiamine deficiency.