Thiamine Deficiency

Medically Reviewed By William C. Lloyd III, MD, FACS

What is thiamine deficiency?

Thiamine deficiency (beriberi) results when your body does not have enough of the vitamin thiamine. Your body requires thiamine to help it break down different types of sugar. Without enough thiamine, you may experience a variety of symptoms that can be serious. Because many foods are supplemented with thiamine, thiamine deficiency is rare in the United States. However, thiamine deficiency is possible in some people with rare genetic conditions, in people who eat very unbalanced diets, in alcoholics, and in some people with kidney disease.

Depending on the level of thiamine deficiency, symptoms can vary greatly. There are two primary types of thiamine deficiency: wet beriberi and dry beriberi. Wet beriberi includes symptoms somewhat like those of congestive heart failure (heart failure is a deterioration of the heart’s ability to pump blood), including difficulty breathing and lower leg swelling. Dry beriberi mainly affects nerves and has symptoms that include weakness (loss of strength) and paralysis.

Thiamine deficiency is usually treated with thiamine supplements and by adjustments to your diet or lifestyle that will help prevent a future occurrence. If the condition is discovered early and treated promptly, a full recovery is likely. In cases when thiamine deficiency is untreated or treated late, serious complications are probable.

Seek prompt medical care if you suspect you might have thiamine deficiency or if you have symptoms of thiamine deficiency, including numbness or tingling (possibly accompanied by weakness, clumsiness, confusion, or difficulty thinking) or symptoms of congestive heart failure, such as swelling in your legs and shortness of breath.

What are the symptoms of thiamine deficiency?

Thiamine deficiency is associated with a wide variety of symptoms, depending on the type of thiamine deficiency. In one type of deficiency, known as wet beriberi, symptoms are similar to those of congestive heart failure. They include difficulty breathing with exercise or exertion or when lying down, and swelling in the legs. In another type of thiamine deficiency, dry beriberi, symptoms include weakness or paralysis of muscles or limbs, changes in thinking, difficulty sensing vibration, and other nervous system symptoms.

Common symptoms of thiamine deficiency (wet beriberi)

If you have wet beriberi thiamine deficiency, you may experience symptoms daily or just once in a while. At times, any of these symptoms may be severe:

  • Difficulty breathing

  • Difficulty breathing when lying down

  • Leg pain and swelling (most noticeable by long-lasting indentations in your skin after you remove your socks)

  • Rapid heart rate (tachycardia)

  • Shortness of breath

Common symptoms of thiamine deficiency (dry beriberi)

If you have dry beriberi thiamine deficiency, you may experience symptoms daily or just once in a while. At times, any of these symptoms may be severe:

  • Confusion or changes in thinking

  • Difficulty sensing vibrations, especially in your hands and feet

  • Difficulty walking

  • Garbled or slurred speech or inability to speak

  • Generalized pain

  • Impaired balance and coordination

  • Numbness or tingling in the arms or legs

  • Repeated jerky eye movements (nystagmus)

  • Vomiting

  • Weakness (loss of strength)

Serious symptoms that might indicate a life-threatening condition

In some cases, thiamine deficiency can be life threatening. Seek immediate medical care (call 911) if you, or someone you are with, have any of these life-threatening symptoms including:

What causes thiamine deficiency?

To function correctly, your body requires the vitamin thiamine. Without enough thiamine, a variety of symptoms can occur, ultimately resulting in death if the deficiency is severe or untreated.

Thiamine deficiency is caused by too little thiamine. This can occur in two ways: either too little thiamine is consumed or too much thiamine is lost. Most diets in the developed world are supplemented with thiamine, making a dietary deficiency of this vitamin very rare. In individuals with incredibly poor or unbalanced diets, such as alcoholics or people in the developing world, it is possible to consume a diet that is deficient in thiamine. In other cases, a genetic condition or kidney condition can result in too much thiamine being lost.

What are the risk factors for thiamine deficiency?

A number of factors increase the risk of developing thiamine deficiency. Most people with risk factors will not get thiamine deficiency because it is very rare, especially in the developed world. Risk factors for thiamine deficiency include:

  • Alcoholism
  • Bariatric surgery
  • Genetic beriberi
  • Kidney disease
  • Living in an impoverished or underdeveloped nation
  • Low socioeconomic status
  • Poor diet
  • Starvation

Reducing your risk of thiamine deficiency

Thiamine deficiency is rare in the developed world because many foods have supplemental thiamine added. Though the disease is uncommon, you can reduce your risk of thiamine deficiency by eating a healthy and varied diet.

How is thiamine deficiency treated?

The only treatment for thiamine deficiency is thiamine supplementation and changes to any underlying dietary habits that may have caused the deficiency. Thiamine supplementation can be given orally or by injection, depending on the type and cause of thiamine deficiency you have.

If identified early and treated promptly, most symptoms associated with thiamine deficiency should resolve. People who have thiamine deficiency should receive long-term monitoring of their thiamine levels to ensure that the deficiency does not return.

What are the potential complications of thiamine deficiency?

Left untreated, or if a thiamine deficiency is critical, complications can be severe and life threatening. Congestive heart failure (deterioration of the heart’s ability to pump blood) is a common complication of untreated wet beriberi. Permanent nervous system complications are also possible, along with coma and psychosis.

You can help minimize your risk of serious complications by following the treatment plan you and your health care professional design specifically for you. Complications of thiamine deficiency include:

  • Coma
  • Encephalopathy
  • Heart failure
  • Permanent nerve damage, which may limit sensation
  • Psychosis
  • Worsening of diabetic neuropathy
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  1. Beriberi. PubMed Health, a service of the NLM from the NIH.
  2. Domino FJ (Ed.) Five Minute Clinical Consult. Philadelphia: Lippincott Williams & Wilkins, 2013.
  3. Collins RD. Differential Diagnosis in Primary Care, 5th ed. Philadelphia: Lippincott, Williams & Williams, 2012.
Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 Jan 11
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