Complete Guide to Thiamine Deficiency

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While relatively uncommon in developed countries, a thiamine deficiency can lead to serious health problems.

Types of Thiamine Deficiency

There are two primary types of thiamine (vitamin B1) deficiency. These include a subclinical deficiency and a severe deficiency called beriberi.

Subclinical B1 Deficiency

Most Americans do not consume the recommended daily allowance of 1.5 milligrams of thiamine each day, which can result in subclinical, or low, thiamine levels.

Symptoms of a Subclinical thiamine deficiency include:

  • Constipation
  • Depression
  • Fatigue
  • Pins and Needles Sensation
  • Numbness in the Legs

Severe B1 Deficiency

A severe deficiency of thiamine is known as beriberi and is relatively uncommon in the United States. This is due to the enrichment of many foods with thiamine. Alcoholics are the only group of Americans who are at major risk of developing beriberi because thiamine is destroyed by the presence of alcohol and sulfites. There are two main categories of beriberi. Dry beriberi affects the nervous system, while wet beriberi affects the cardiovascular system.

Symptoms of dry beriberi include:

  • Trouble when walking
  • Loss of feeling in the hands and feet
  • Mental confusion
  • Speech problems
  • Pain
  • Tingling
  • Vomiting

Symptoms of wet beriberi include:

  • Shortness of breath upon wakening at night
  • Engorged heart
  • Shortness of breath
  • Swelling in the legs

Other Causes of B1 Deficiency

Breastfed infants can experience a thiamine deficiency if their mother has low thiamine levels. Some formula-fed infants may also develop a thiamine deficiency if the formula does not contain adequate amounts of this vitamin.Genetic beriberi is an exceptionally rare condition that can be passed down through family members. Individuals with genetic beriberi do not have the ability to properly absorb thiamine from the foods they eat. Many times diagnosis of genetic beriberi does not occur quickly because healthcare practitioners do not always look for a vitamin B1 deficiency in people who are not alcoholics.


Diagnosis of subclinical thiamine deficiency and beriberi include a physical examination. Your doctor may also perform a blood test to measure the levels of thiamine in the blood. Urine tests are often administered to see if thiamine is passing through the urine.


The goal of thiamine deficiency treatment is to increase your intake of thiamine so the deficiency can be reversed. To treat thiamine deficiency, your doctor will mostly likely recommend a thiamine or B-complex vitamin supplement. Blood tests may be done after you have been taking a thiamine supplement to determine if your thiamine levels have returned to normal. Your doctor may also suggest you speak with a registered dietitian to create a meal plan that will help you to include thiamine rich foods in your diet.

How to Prevent a Deficiency

Most cases of B1 deficiency can be prevented by consuming a diet that includes plenty of foods rich in thiamine. A B-complex vitamin supplement is also an option, if you are concerned your intake of this or any of the B vitamins is insufficient.

Speak to Your Doctor

If you suspect you may have a thiamine deficiency, please speak to your doctor. Typically, doctors do not look for a deficiency of this vitamin in non-alcoholics, so it is best to request an examination and blood test if this is something you are concerned about.

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Complete Guide to Thiamine Deficiency