Thiamine deficiency

Lore & Background

Thiamine deficiency is a medical condition of low levels of thiamine (vitamin B1). A severe and chronic form is known as beriberi. The name beriberi was possibly borrowed in the 18th century from the Sinhalese phrase බැරි බැරි (bæri bæri, 'I cannot, I cannot'), owing to the weakness caused by the condition. The two main types in adults are wet beriberi and dry beriberi. Wet beriberi affects the cardiovascular system, resulting in a fast heart rate, shortness of breath, and leg swelling. Dry beriberi affects the nervous system, resulting in numbness of the hands and feet, confusion, trouble moving the legs, and pain. A form with loss of appetite and constipation may also occur. Another type, acute beriberi, found mostly in babies, presents with loss of appetite, vomiting, lactic acidosis, changes in heart rate, and enlargement of the heart.

Reader's Guide

Thiamine deficiency is significant because it causes beriberi, a condition that has been described for thousands of years in Asia and became more common in the late 1800s with increased rice processing. It remains relatively common in sub-Saharan Africa and outbreaks have been seen in refugee camps. The deficiency can lead to Wernicke encephalopathy and Korsakoff syndrome, which are forms of dry beriberi. Wernicke's encephalopathy is the most frequently encountered manifestation of thiamine deficiency in Western society, often in alcoholics. Treatment with thiamine supplementation generally resolves symptoms in a few weeks. The disease may be prevented at the population level through the fortification of food. Risk factors include a diet of mostly white rice, alcoholism, dialysis, chronic diarrhea, and taking high doses of diuretics. In rare cases, it may be due to a genetic condition that results in difficulties absorbing thiamine found in food. Diagnosis is based on symptoms, low levels of thiamine in the urine, high blood lactate, and improvement with thiamine supplementation.

Did You Know?

• The name beriberi was possibly borrowed in the 18th century from the Sinhalese phrase බැරි බැරි (bæri bæri, 'I cannot, I cannot').
• Wernicke encephalopathy and Korsakoff syndrome are forms of dry beriberi.
• Infantile beriberi usually occurs between two and six months of age in children whose mothers have inadequate thiamine intake.