What Are Thiamine Deficiency Symptoms?

Thiamine, the common name for vitamin B1, is a vitamin which assists in both nerve function and the processing of food-derived energy sources, like glucose. This vitamin must be obtained through the diet, and when thiamine intake or absorption is inadequate, a number of different symptoms tend to occur. Exact thiamine deficiency symptoms depend largely on the cause of the deficiency. The thiamine deficiency known as beriberi is caused by malnutrition, and can produce symptoms which affect either the nervous system, such as mobility problems and vomiting, or the cardiovascular system, such as shortness of breath and an elevated heart rate. Thiamine deficiency symptoms which are caused by alcohol consumption are generally brain-related, including disorientation and trouble controlling some muscles.

One form of thiamine deficiency, known as beriberi, occurs when an individual does not ingest enough thiamine, either because he consumes a diet lacking in thiamine-enriched foods or because another factor such as weight-loss surgery has impeded his ability to absorb nutrients. It should be noted that in developed countries, many foods are enriched with thiamine, making beriberi rare. When it does occur, it can affect the nervous system or the cardiovascular system. Thiamine deficiency affecting the nervous system is known as dry beriberi, while a deficiency that affects the cardiovascular system is known as wet beriberi.

In the case of dry beriberi, thiamine deficiency symptoms include mobility problems, tingling or numbness in the limbs, disorientation, uncontrollable movement of the eyes, discomfort, and vomiting. Thiamine deficiency symptoms related to wet beriberi can include elevated heart rate, shortness of breath which may wake the sufferer at night, and swelling of the lower extremities. If left untreated, dry beriberi can cause irreversible nerve damage, while wet beriberi can lead to congestive heart failure or even death.

Alcoholism can also lead to thiamine deficiency, either because the alcoholic individual fails to eat a diet containing a sufficient level of vitamins, or because organ damage caused by alcohol consumption prevents thiamine absorption. Alcohol-related thiamine deficiency is a form of dry beriberi which specifically affects the brain. Early on, this form of thiamine deficiency tends to take the form of a condition called Wernicke’s encephalopathy. Thiamine deficiency symptoms related to Wernicke’s encephalopathy can include disorientation, difficulty controlling the muscles of the legs and the eyes, and blurry or double vision.

If left untreated, Wernicke’s encephalopathy can progress into a condition called Korsakoff syndrome. This condition occurs when certain parts of the brain used in forming new memories are damaged by thiamine deficiency. Those with Korsakoff syndrome may not be able to remember new events, and may also lose old memories. Additionally, they may hallucinate or believe fabricated stories to be memories. While it may be possible to recover partially or even wholly from Korsakoff syndrome, chances of recovery are usually greatly reduced among those who have suffered from the condition for more than two years.