Signs And Symptoms Of Vitamin B1 (Thiamine) Deficiency

Signs and symptoms of a thiamine deficiency.

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“Vasan, Sarayu, and Scott C. Dulebohn. “Wernicke Encephalopathy.” (2017).”

Vitamin B1 allows the carbohydrates and protein that you consume to be used for energy creation or metabolism. It is needed for the functioning, growth, and development of cells in your body. The body doesn’t make its own vitamin B1 and stores very small quantities of it as well, so you need to consume thiamine through your diet on a regular basis to ensure a steady supply.[ref]Thiamin. Office of Dietary Supplements.[/ref]

Vitamin B1 or thiamine is something your body needs to keep your energy metabolism going. Without it, the growth and development of your body’s cells will take a hit. It isn’t a vitamin your body can produce naturally, so getting adequate amounts is critical. Fail to do that and you’ll soon start to see the signs of your body protesting or weakening.


Neurological Problems Linked To Dry Beriberi

If left unchecked, beriberi could result in psychosis, congestive heart failure, coma, or even death.[ref]Beriberi. U.S. National Library of Medicine.[/ref]

Your nervous system is fueled by glucose. And not getting enough thiamine can mean its supply is inadequate. The result? A condition called beriberi that occurs due to thiamine deficiency. There are two kinds of beriberi. Dry beriberi affects the nervous system and has the following neurological symptoms:[ref]Guilland, Jean-Claude. “Vitamin B1 (thiamine).” La Revue du praticien 63, no. 8 (2013): 1074-5.[/ref] [ref]Beriberi. U.S. National Library of Medicine.[/ref]

  • Loss of sensation in extremities (feet/hands)
  • Tingling sensation
  • Trouble with walking
  • Loss of muscular function in lower legs
  • Paralysis of your lower legs
  • Speech difficulty
  • Confusion
  • Pain
  • Vomiting
  • Unusual eye movements or nystagmus

If you’re a heavy drinker or an alcoholic, you might also experience some nerve pain from the heavy drinking. This pain is compounded by having a thiamine deficiency.[ref]Thiamine. U.S. National Library of Medicine.[/ref]

Cardiovascular Symptoms Associated With Wet Beriberi

You’ll find the nutrient in foods like fortified or enriched breakfast cereals and grains, in pork, seafood like muscles or trout, sunflower seeds, soy products, and yeast extract. The recommended dietary allowances (RDA) for thiamine is 1.1-1.2 mg a day for adults and 1.4 mg for pregnant women and nursing mothers.[ref]Thiamin. Office of Dietary Supplements.[/ref] [ref]Food Sources of Thiamin (Vitamin B1). Dietitians of Canada.[/ref]


A vitamin B1/thiamine deficiency can also result in a condition called wet beriberi. The potentially dangerous symptoms of this condition are easily missed by many. This is because some of its symptoms could be confused with other problems like routine fatigue. Wet beriberi affects your cardiovascular system. You may see one or more of these signs of the thiamine deficiency resulting in wet beriberi:[ref]Essa, Essa, Michael R. Velez, Sakima Smith, Shivraman Giri, Subha V. Raman, and Richard J. Gumina. “Cardiovascular magnetic resonance in wet beriberi.” Journal of Cardiovascular Magnetic Resonance 13, no. 1 (2011): 41.[/ref] [ref]Beriberi. U.S. National Library of Medicine.[/ref]

  • Shortness of breath when you are doing any physical activity
  • Night wakings due to shortness of breath
  • Weakness
  • Swelling in the lower legs
  • Low blood pressure or hypotension
  • Tachycardia or a rapid heart rate
  • Lactic acidosis or lactate buildup in your blood, causing your blood pH to drop

Ignoring these symptoms may sometimes cause rapid deterioration in some people due to the collapse of the circulatory system. Fluid buildup in the lungs or pulmonary edema is also a possibility. Look out for extreme shortness of breath, coughing with blood, palpitations, and chest pain. Circulatory system failure and pulmonary edema can be potentially fatal quite quickly and must be treated with the utmost urgency. Call an ambulance and head straight to the emergency room. Remember, while it is potentially fatal, it is also reversible and can be safely managed if noticed in time.


Cold Extremities, Low BP, And Kidney Problems Linked To Shoshin Beriberi

Shoshin beriberi or acute pernicious beriberi is another less common form of beriberi associated with vitamin B1 deficiency. Like wet beriberi, it causes cardiac problems but of a different kind.[ref]Engbers, J. G., G. P. Molhoek, and A. C. Arntzenius. “Shoshin beriberi: a rare diagnostic problem.” Heart 51, no. 5 (1984): 581-582.[/ref] The repercussions of this include:[ref]Vitamin B1 deficiency. BMJ Best Practice.[/ref] [ref]Meurin, P. “Shoshin beriberi. A rapidly curable hemodynamic disaster.” Presse medicale (Paris, France: 1983) 25, no. 24 (1996): 1115-1118.[/ref]

  • Low blood pressure
  • Cold and clammy hands and feet
  • Renal shutdown/kidney failure
  • Severe metabolic acidosis, a condition where your kidneys aren’t flushing enough acid from your system
  • Cardiac shock and heart failure, a result of leaving this beriberi unmanaged

Vomiting, Restlessness, And Breathing Trouble From Infantile Thiamine Deficiency

In a milder version of infantile beriberi, an infant typically aged 4–6 months, may lose their voice temporarily.[ref]Thiamine deficiency and its prevention and control in major emergencies. World Health Organization.[/ref]


A baby could develop a thiamine deficiency if they are being exclusively breastfed and their mother has a thiamine deficiency. Symptoms include:[ref]Thiamine deficiency and its prevention and control in major emergencies. World Health Organization.[/ref]

  • Constipation (mild or severe)
  • Vomiting
  • Restlessness
  • Crying
  • Generalized edema
  • Breathing trouble
  • Cardiac disturbance
  • Gastrointestinal problems
  • Reduced urine output

This is an easily cured problem but is very risky if left untreated. The symptoms progress rapidly and the fatality rate is quite high, so do act on it immediately. Babies aged 1–3 months are especially vulnerable.


Older infants might have symptoms resembling bacterial meningitis, including:

  • Stiffness of the neck
  • Convulsions
  • Sweating
  • Vomiting

Abnormal Gait, Slurred Speech, And Confusion From Wernicke Encephalopathy

This acute neurological problem is a severe form of dry beriberi and results in a range of symptoms affecting both your central and peripheral nervous system. This condition, too, could be life-threatening. These are symptoms/signs typical of this condition:[ref]Vasan, Sarayu, and Scott C. Dulebohn. “Wernicke Encephalopathy.” (2017).[ref]What is ataxia?. National Ataxia Foundation.[/ref]

  • Repetitive, uncontrolled eye movements or nystagmus
  • Lack of coordination
  • Slurred speech
  • Tremors
  • Trouble with walking
  • Gait abnormalities
  • Loss of/weakening of fine motor skills, which you need to button clothes, use scissors, type on a keyboard, hold a small item, or even write
  • Trouble swallowing/eating
  • Confusion
  • Heart problems may also develop

People with Wernicke encephalopathy may also develop signs of Korsakoff syndrome like psychosis, delirium and permanent memory loss. While two different conditions, these two tend to occur together as a result of brain damage from thiamine deficiency.[ref]Martel, Julianna L., and David S. Franklin. “Vitamin, B1 (Thiamine).” (2017).[/ref] [ref]Wernicke-Korsakoff syndrome. U.S. National Library of Medicine.[/ref]

Causes Of Vitamin B1 Deficiency And At-Risk Groups

You could wind up with a vitamin B1 deficiency because you’ve been eating poorly or have a deficient diet. But it might also be because your body isn’t properly absorbing the nutrients from the food due to an underlying health problem like an intestinal or stomach disorder.[ref]Guilland, Jean-Claude. “Vitamin B1 (thiamine).” La Revue du praticien 63, no. 8 (2013): 1074-5.[/ref] [ref]Thiamine. U.S. National Library of Medicine.[/ref][ref]Thiamin. Office of Dietary Supplements.[/ref] Here’s a look at those most at risk of developing such a deficiency:

  • Those with malabsorption syndromes which prevent the body from properly using or retaining the thiamine consumed via food or supplements.
  • Chronic alcoholics
  • Elderly people
  • Anyone with HIV/AIDS
  • Diabetics
  • Pregnant women who have experienced a lot of vomiting over an extended period (protracted vomiting)
  • Anyone who has had bariatric surgery
  • Those with cirrhosis of the liver
  • Those undergoing hemodialysis treatments because of kidney problems
  • Heavy tea and coffee drinkers who also have a diet low in thiamine and vitamin C, which seems to prevent the tannins in the beverages from hampering absorption of vitamin B1.
  • People who have been chewing betel nuts for a long time. This habit is common in some parts of the world like Asia and causes a thiamine deficiency. The areca nut alters thiamine so it is no longer as usable by the body.
  • People who consume a lot of raw fish and shellfish. Chemicals present in the raw seafood alter thiamine absorption. If you cook your seafood, however, this doesn’t happen. Small amounts of raw seafood are also unlikely to cause a problem.

Treating A Vitamin B1 Deficiency

Treating a thiamine deficiency may involve a regimen of supplementation and any other treatment needed for you depending on the severity of your symptoms. Typically, the World Health Organization suggests 10 mg thiamin (oral doses) every day for a week, then 3–5 mg a day for 6 weeks to overcome a mild vitamin B1 deficiency.[ref]Thiamin. Office of Dietary Supplements.[/ref]

If your problem is more severe, you may need to be given 50–100 mg of the vitamin intravenously. After this, your regimen will involve a week of 10 mg a day given intramuscularly, followed by 6 weeks of 3–5 mg a day of oral thiamine.[ref]Thiamin. Office of Dietary Supplements.[/ref] Infants will be given smaller doses than these.