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How Vitamin B1 Works

The discovery of thiamin was the key that unlocked the mystery of a disease -- a disease born of technology, but called by the simple name beriberi. The word itself means weakness in an East Indian dialect. In this article, we'll take a look at the importance of thiamin in preventing disorders of the nervous system and other illnesses, and we'll learn just how much thiamin is recommended for daily intake. Here's a preview.
  • What is Vitamin B1?

    Vitamin B1, or thiamin, is an important coenzyme that helps the body convert food into energy. It also assists in manufacturing fat and metabolizing protein. Thiamin is necessary to maintain normal function in the nervous system.

  • Benefits of Vitamin B1

    Thiamin plays a part in the chain of reactions that provides energy for the body. It is thought to be beneficial for people suffering from Alzheimer's disease and older adults with mental impairment. It may also improve the mental function of epilepsy sufferers who take the drug phenytoin.

  • Foods That Contain Vitamin B1

    Most foods contain only very small amounts of thiamin. However, it can be found in "enriched" foods such as breads and cereals. Thiamin occurs naturally in pork, oysters, green peas, and lima beans.

  • Vitamin B1 Deficiency

    A thiamin deficiency leads to beriberi, a debilitating and potentially fatal disease. "Dry beriberi" is characterized by numbness, muscle weakness, loss of appetite, and disorders of the nervous system. "Wet beriberi" causes fluid accumulation and can lead to heart failure.
Vitamin B1 isn't the only nutrient you need for overall health. Check out these links for more information about essential vitamins.
  • Vitamin A, or retinol, plays a vital role in vision. Learn more in How Vitamin A Works.
  • In How Vitamin B2 Works, read about how B2, or riboflavin, works in concert with its B-complex relatives to metabolize carbohydrates, fats, and proteins.
  • Vitamin B3, or niacin, acts as a coenzyme, assisting other substances in the conversion of food into energy. Learn more in How Vitamin B3 Works.
  • Vitamin B5, or pantothenic acid, can be found in all living cells and in all foods. Learn about its importance to your diet in How Vitamin B5 Works.
  • Vitamin B6 is actually three substances, pyridoxine, pyridoxamine, and pyridoxal, that work to metabolize protein and amino acids. Read more in How Vitamin B6 Works.
  • To learn about the many vitamins in our diet, how much you should be eating, and where to find them, go to our general Vitamins page.
  • If you're looking for the best prices on B vitamins, click here.
This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.

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Beriberi, a debilitating, often fatal ailment, wasn't a serious health problem among the rice-eating peoples of Asia until the end of the 19th century. But then mills began to polish rice -- a process that removes the outer brown layers of the grain, leaving behind smooth, white kernels. Rice stripped of this outer layer of bran has lost much of its thiamin.

Soon after the practice of refining began, the incidence of beriberi rose to epidemic levels in Asia. A similar situation occurred in countries where wheat was a dietary staple when refined white flour began to replace whole-wheat flour. The increased prevalence of beriberi spurred efforts to find its cause and cure. Still, the search took almost 50 years.

Polished rice is missing its outer layer of bran, stripping it of much of its thiamin.
© 2007 Publications International, Ltd.
Polished rice is missing its outer layer of bran, stripping it of much of its thiamin.

A medical officer in the Japanese navy, named K. Takaki, was the first to suspect the relationship between diet and beriberi. In the 1880s, Takaki began investigating the disease, which afflicted large numbers of Japanese sailors on long voyages -- a situation reminiscent of scurvy (see page 216). To test his belief that diet was at fault, Takaki added meat and milk to the rice diet of the sailors. Only a few men came down with the malady -- those who refused to eat the milk and meat.

Further evidence came from Java, where the Dutch physician Cristiaan Eijkman found that chickens fed polished rice exhibited symptoms similar to those of beriberi. When he fed the chickens unpolished rice, the symptoms disappeared. Eijkman then tried the same thing on people and confirmed that unpolished rice could prevent and cure beriberi.

Still, it wasn't until 1910 that a search for the mystery substance in unpolished rice began in earnest. Chemist Robert Williams analyzed liquid extracted from rice polishings, painstakingly testing each substance from it for its effect on polyneuritis -- the chicken disease similar to beriberi. In 1934, Williams isolated the substance that would solve the beriberi riddle: the vitamin thiamin.

Functions

Like other B-complex vitamins, thiamin acts as a biological catalyst, or coenzyme. As a coenzyme, thiamin participates in the long chain of reactions that provides energy and heat for the body. It also helps the body manufacture fats and metabolize protein, and it is needed for the normal functioning of the nervous system.

In addition to preventing beriberi, thiamin might also be useful for people suffering from Alzheimer's disease. Go to the next page to learn more about thiamin's therapeutic value.

You need a balance of essential vitamins to maintain overall health. Visit the links below to learn more about these vital nutrients.
  • In How Biotin Works, learn how biotin acts as a coenzyme in several metabolic reactions, such as the metabolism of fats and carbohydrates.
  • Read How Folate Works to learn about folacin, folic acid, and folate and how a folate deficiency can cause megaloblastic anemia.
  • Vitamin B12, also called cyanocobalamin or cobalamin, is essential because it assists folate in making DNA and RNA. Read more in How Vitamin B12 Works.
  • Vitamin C, or ascorbic acid, is good for more than just easing the common cold. Learn more in How Vitamin C Works.
  • Vitamin D is necessary to hold of rickets, but if you get enough sunshine, your body can make its own vitamin D supply. Learn more in How Vitamin D Works.

  • To learn about the many vitamins in our diet, how much you should be eating, and where to find them, go to our general Vitamins page.
  • If you're looking for the best prices on B vitamins, click here.
This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.

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Thiamin may be helpful to people with Alzheimer disease. It mimics acetylcholine, a neurotransmitter critical to memory. Alzheimer 's patients who take 3 to 8 g per day of thiamin have better mental function and fewer senility and memory problems. Any older adult with mental impairment may benefit from additional thiamin, too.

Tiamin might be beneficial for people with Alzheimer disease and older adults with mental impairment.
© 2007 Publications International, Ltd.
Thiamin might be beneficial for people with Alzheimer's disease and older adults
with mental impairment.

People who suffer from epilepsy and take the drug phenytoin may benefit from taking 50 to 100 mg of thiamin every day. In a four-year study, epileptics taking these doses had better mental function and test scores than those who took folate or a placebo.

Because thiamin plays a part in the reactions that supply the body with energy, "stress formula" supplements often tout it as a cure for stress and fatigue. Although thiamin does not provide energy itself, it helps turn the food you eat into energy. If you're marginally low in thiamin, a supplement will help squeeze more energy out of your food. But deficiencies aren't common if you eat a varied diet of whole foods. Take a look at the thiamin values for the foods listed on the next page,
Foods That Contain Vitamin B1, before assuming you have a deficiency.

Thiamin can be found in "enriched" foods, although high cooking temperatures can destroy thiamin. Go to the next page to learn which foods are a good source of this nutrient.

Vitamin B1 is just one of many vital nutrients you need to maintain your health. Visit these links to learn more about other essential vitamins.
  • Vitamin A, or retinol, plays a vital role in vision. Learn more in How Vitamin A Works.
  • In How Vitamin B2 Works, read about how B2, or riboflavin, works in concert with its B-complex relatives to metabolize carbohydrates, fats, and proteins.
  • Vitamin B3, or niacin, acts as a coenzyme, assisting other substances in the conversion of food into energy. Learn more in How Vitamin B3 Works.
  • In How Vitamin E Works, learn about this important antioxidant with far-reaching health benefits.
  • Vitamin K is important in allowing your blood to clot properly. Learn more in How Vitamin K Works.

  • To learn about the many vitamins in our diet, how much you should be eating, and where to find them, go to our general Vitamins page.
  • If you're looking for the best prices on B vitamins, click here.
This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.

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The term "enriched" on food labels means that three B vitamins (thiamin, niacin, and riboflavin) plus one mineral (iron) have been added back to that food to make up for some of the nutrients that were lost during processing. Enriched breads and cereals are, therefore, good sources of thiamin. Pork, oysters, green peas, and lima beans are also good sources. Most other foods contain only very small amounts of thiamin.

A high cooking temperature easily destroys thiamin. As a water-soluble vitamin, thiamin also leaches out of food into cooking water. To preserve the thiamin in foods, cook food over low temperatures in as small an amount of water for the shortest time possible. Steaming and microwaving keep losses to a minimum and often better preserve the natural flavor, too.

Adding baking soda to vegetables to preserve their bright green color destroys their thiamin content.
© 2007 Publications International, Ltd.
Adding baking soda to vegetables to preserve their bright green color
destroys their thiamin content.

To help retain their bright green color, some people add baking soda to vegetables when they cook them. This is not a good idea. Not only does the baking soda make the vegetables lose their shape and consistency, but it destroys the thiamin content. Sulfites, used as preservatives, also destroy thiamin.

Dietary Requirements

The amount of thiamin your body requires depends on the number of calories you eat, particularly the calories you get from carbohydrates. You need 0.5 mg of thiamin for every 1,000 calories (assuming an average intake of carbohydrates). Thiamin intake should be at least 1.0 mg per day even if your total calorie intake is less than 2,000. By increasing your intake of carbohydrates, you also increase your need for thiamin, but your intake of thiamin usually increases, too.

The RDA for thiamin is 1.2 mg for men and 1.1 mg for women until age 50. A pregnant or nursing woman, who needs more calories, requires more thiamin than other women. A varied, well-balanced diet easily supplies the thiamin needed.

This chart lists foods that are good sources of thiamin.

Food Quantity
Thiamin (mg)
Pistachio nuts 1/2 cup
0.54
Watermelon 1 slice 0.39
Filberts or hazelnuts 1/2 cup 0.34
Oatmeal, ready-to-serve 1 cup 0.28
Macaroni, cooked, enriched 1 cup 0.28
Cashews, roasted 1/2 cup 0.28
Peas, green, cooked 1 cup 0.28
Fish 3 ounces 0.27-0.57
Rice, enriched, cooked 1 cup 0.25
Sunflower seeds 1 tablespoon 0.21

Vitamin B1 deficiency causes beriberi, a disease that can be debilitating and even fatal. Keep reading to learn more about vitamin B1 deficiencies.

Thiamin is just one piece of the puzzle when it comes to the nutrients you need for good health. Check out the links below to learn more about these essential vitamins.
  • Vitamin B5, or pantothenic acid, can be found in all living cells and in all foods. Learn about its importance to your diet in How Vitamin B5 Works.
  • Vitamin B6 is actually three substances, pyridoxine, pyridoxamine, and pyridoxal, that work to metabolize protein and amino acids. Read more in How Vitamin B6 Works.
  • In How Biotin Works, learn how biotin acts as a coenzyme in several metabolic reactions, such as the metabolism of fats and carbohydrates.
  • Read How Folate Works to learn about folacin, folic acid, and folate and how a folate deficiency can cause megaloblastic anemia.
  • Vitamin B12, also called cyanocobalamin or cobalamin, is essential because it assists folate in making DNA and RNA. Read more in How Vitamin B12 Works.
  • To learn about the many vitamins in our diet, how much you should be eating, and where to find them, go to our general Vitamins page.
  • If you're looking for the best prices on B vitamins, click here.
This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.

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Numbness, muscle weakness, loss of appetite, and disorders of the nervous system such as irritability, memory loss, and depression, characterize the form of beriberi known as "dry beriberi." In contrast, "wet beriberi" features fluid accumulation, especially in the lower legs. This severe form of the disease interferes with the heart and the circulatory system and can eventually cause heart failure. In childhood, thiamin deficiency stunts growth.

Numbness, muscle weakness, and loss of appetite are all signs of
©2007 Publications International, Ltd.
Numbness, muscle weakness, and
loss of appetite are all signs of dry beriberi.

Almost all elderly people have lower than optimal body levels of thiamin. This may be due to the decline in absorption often seen as people age, or may be due to a restricted diet as people eat less of a variety of foods. People with cardiovascular diseases also have an increased need for thiamin supplementation.

Severe thiamin deficiency seldom occurs today in the Western world, except among alcoholics, who eat little or no food for extended periods of time. They can develop a pattern of neurologic symptoms known as Wernicke-Korsakoff syndrome, involving the nervous system and causing a form of psychosis.

Thiamin deficiency may also occur in people who make poor food choices through ignorance, neglect, or poverty. Diets deficient in thiamin are often deficient in other B vitamins as well, because the B vitamins exist in many of the same foods. Highly processed foods are the main culprit, adding carbohydrates to the diet without the B vitamins needed to process them.

Doses of thiamin two to five times the RDA are used to treat a deficiency. In developed countries, deficiencies are most commonly seen in children receiving chemotherapy; these are easily resolved with supplementation. There are no known toxicity problems with thiamin in large doses.

But deficiencies don't need to be severe to cause problems. Even mildly low levels can bring about delirium or problems with mental function. Thiamin is partially responsible for energy production, including energy for the brain. Without it, the brain just doesn't work as well. It's believed that up to 30 percent of patients who are admitted to mental institutions have a thiamin deficiency.

Thiamin deficiency is rare in the United States, but now you know what to look out for and why thiamin is so important to your health. Make sure you're getting the right amounts of thiamin in your diet to keep beriberi at bay.

Vitamin B1 is just one of many vitamins you need for overall health. Follow these links to learn more about the nutrients your body needs.
  • In How Vitamin B2 Works, read about how B2, or riboflavin, works in concert with its B-complex relatives to metabolize carbohydrates, fats, and proteins.
  • Vitamin B3, or niacin, acts as a coenzyme, assisting other substances in the conversion of food into energy. Learn more in How Vitamin B3 Works.
  • Vitamin B5, or pantothenic acid, can be found in all living cells and in all foods. Learn about its importance to your diet in How Vitamin B5 Works.
  • Vitamin B6 is actually three substances, pyridoxine, pyridoxamine, and pyridoxal, that work to metabolize protein and amino acids. Read more in How Vitamin B6 Works.
  • In How Biotin Works, learn how biotin acts as a coenzyme in several metabolic reactions, such as the metabolism of fats and carbohydrates.
  • To learn about the many vitamins in our diet, how much you should be eating, and where to find them, go to our general Vitamins page.
  • If you're looking for the best prices on B vitamins, click here.
ABOUT THE AUTHOR:

Jennifer Brett, N.D. is director of the
Acupuncture Institute for the University of Bridgeport, where she also serves on the faculty for the College of Naturopathic Medicine. A recognized leader in her field with an extensive background in treating a wide variety of disorders utilizing nutritional and botanical remedies, Dr. Brett has appeared on WABC TV (NYC) and on Good Morning America to discuss utilizing herbs for health.


This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.

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