Thiamine deficiency (causing beriberi and other problems) is most common among people whose diet mainly consists of white rice or highly processed carbohydrates in countries with high rates of food insecurity and among people with alcohol use disorder.
A diet consisting mainly of white flour, white sugar, and other highly processed carbohydrates can cause thiamine deficiency.
At first, people have vague symptoms such as fatigue and irritability, but a severe deficiency (beriberi) can affect the nerves, muscles, heart, and brain.
The diagnosis is based on symptoms and a favorable response to thiamine supplements.The diagnosis is based on symptoms and a favorable response to thiamine supplements.
Thiamine supplements, usually taken by mouth, can correct the deficiency.Thiamine supplements, usually taken by mouth, can correct the deficiency.
Thiamine (vitamin B1) is widely available in the diet. It is essential for the processing (metabolism) of carbohydrates (to produce energy), proteins, and fats and for normal nerve and heart function. Thiamine is not toxic, so consuming excess amounts of thiamine is not a concern. Good sources of thiamine include dried yeast, whole grains, meat (especially pork and liver), enriched cereals, nuts, legumes, and potatoes.
Thiamine deficiency often occurs with other B vitamin deficiencies.
Causes of Thiamine Deficiency
Thiamine deficiency may result from
A deficiency of thiamine in the diet
Young adults with severe anorexia nervosa, people who are significantly undernourished, and people whose diet consists mainly of highly processed carbohydrates (such as polished white rice, white flour, and white sugar) may not consume enough thiamine. Polishing rice removes almost all of the vitamins.
People who consume excessive amounts of alcohol often substitute alcohol for food and thus do not consume enough thiamine, are at high risk of developing this deficiency. Also, alcohol may interfere with the absorption and metabolism of this vitamin and may increase the body’s need for thiamine.
Thiamine deficiency may also result from
Disorders or conditions that increase the body’s need for thiamine, such as an overactive thyroid gland (hyperthyroidism), pregnancy, breastfeeding, strenuous exercise, and fever
Disorders that interfere with the metabolism of the vitamin, such as liver disorders
Disorders that prevent thiamine from being absorbed, such as diarrhea that lasts a long time
Symptoms of Thiamine Deficiency
Early symptoms of thiamine deficiency are vague. They include fatigue, irritability, poor memory, loss of appetite, sleep disturbances, abdominal discomfort, and weight loss.
Eventually, a severe thiamine deficiency (beriberi) may develop, characterized by nerve, heart, and brain abnormalities. Different forms of beriberi cause different symptoms.
Dry beriberi
Nerve and muscle abnormalities develop. Symptoms include a prickling (pins-and-needles) sensation in the toes, a burning sensation in the feet that is particularly severe at night, and leg cramps and pain. Muscles may become weak and waste away (atrophy). If the deficiency worsens, the arms are also affected.
Wet beriberi
Heart abnormalities develop. The heart pumps more blood and beats faster. Blood vessels widen (dilate), making the skin warm and moist. Because the heart cannot continue to work at this level, heart failure eventually develops. As a result, fluid accumulates in the legs (as edema) and in the lungs (as congestion), and blood pressure may fall, sometimes leading to shock and death.
Brain abnormalities
Thiamine deficiency causes brain abnormalities primarily in people with alcohol use disorder. Brain abnormalities may be present without causing any symptoms until something happens to worsen the thiamine deficiency, such as binge drinking alcohol. Brain abnormalities can also cause symptoms after a person with alcohol use disorder is given carbohydrates intravenously. Symptoms occur because these extra carbohydrates further increase thiamine requirements. These brain abnormalities are called the Wernicke-Korsakoff syndrome, which has 2 parts:
Wernicke encephalopathy causes confusion, apathy, difficulty walking, and eye problems, including involuntary eye movements (nystagmus) and partial paralysis of the muscles that move the eyes. If Wernicke encephalopathy is not promptly treated, symptoms may worsen, resulting in coma and even death.
Korsakoff psychosis causes memory loss for recent events, confusion, and a tendency to make up facts to fill in gaps in memories (confabulation).
Infantile beriberi
This form occurs in infants (usually by age 3 to 4 weeks) who are breastfed by a mother who has a thiamine deficiency. In these infants, heart failure may occur suddenly. They may lose their voice (aphonia) to some degree, and they may not have certain reflexes.
Diagnosis of Thiamine Deficiency
A doctor's examination
Relief of symptoms when thiamine supplements are taken
The diagnosis of thiamine deficiency is based on symptoms and the results of a physical examination, with emphasis on examination of the heart and nervous system.
Tests to confirm the diagnosis are not readily available. Blood tests to measure electrolyte levels are usually done to exclude other possible causes of the symptoms.
The diagnosis is confirmed if thiamine supplements relieve symptoms.
Treatment of Thiamine Deficiency
Thiamine supplements Thiamine supplements
All forms of thiamine deficiency are treated with thiamine supplements. They are usually given by mouth. They are given intravenously if symptoms are severe. Because deficiency are treated with thiamine supplements. They are usually given by mouth. They are given intravenously if symptoms are severe. Becausethiamine deficiency often occurs with other B vitamin deficiencies, multivitamins are usually given for several weeks. People are encouraged to eat healthily and are advised to consume 1 to 2 times the daily recommended intake of vitamins. They should not drink any alcohol.
Wernicke-Korsakoff syndrome, a medical emergency, is treated with high doses of thiamine given intravenously or by injection into a muscle (intramuscularly) for several days. Use of alcohol should be stopped.Wernicke-Korsakoff syndrome, a medical emergency, is treated with high doses of thiamine given intravenously or by injection into a muscle (intramuscularly) for several days. Use of alcohol should be stopped.
When people who may have a thiamine deficiency, particularly people with alcohol use disorder, must be fed intravenously, they are given thiamine supplements first. These intravenous solutions contain glucose. Because deficiency, particularly people with alcohol use disorder, must be fed intravenously, they are given thiamine supplements first. These intravenous solutions contain glucose. Becausethiamine is needed to process (metabolize) glucose, glucose may trigger or worsen symptoms of thiamine deficiency. Giving them thiamine supplements first can prevent Wernicke-Korsakoff syndrome from developing or worsening.deficiency. Giving them thiamine supplements first can prevent Wernicke-Korsakoff syndrome from developing or worsening.
With treatment, most people recover completely. In some people with Wernicke-Korsakoff syndrome, some brain damage is permanent. Symptoms of beriberi may recur years after apparent recovery.
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