views updated May 14 2018









Parental concerns



Thiamin, also spelled thiamine and previously known as vitamin B1, is a micronutrient essential for the metabolism of carbohydrates that converts sugar into energy for the body and for normal nerve and heart function. Thiamine deficiency causes a condition known as beriberi or beri-beri. The initial symptoms are very vague. The first indication of thiamine deficiency may be simple fatigue. As the condition becomes more advanced, there is a wide range of symptoms, affecting many organ systems. These include, but are not limited to chest pains, memory loss, muscle cramps and weakness. In more advanced cases, muscle atrophy and heart failure may be present.


Thiamin has several important functions. It works with other B-group vitamins to help release energy from the food we eat and it keeps nerves and muscle tissue healthy. In the form of thiamin pyrophosphate (TPP), it plays an essential role as a cofactor in key reactions breaking down food and converting carbohydrate into energy for the body (carbohydrate metabolism). Like other B-complex vitamins, thiamin is also considered an anti-stress vitamin because it is believed to enhance the activity of the immune system and increase the body’s ability to resist stressful conditions.

Thiamin also plays a therapeutic role in the prevention or treatment of the following diseases:

  • alcoholism
  • Alzheimer’s disease
  • congestive heart failure
  • depression
  • epilepsy
  • fibromyalgia
  • AIDS
  • multiple sclerosis


Thiamin is a micronutrient, meaning a nutrient needed in very small amounts, found in a variety of animal and plant foods. It is a water-soluble vitamin that it is eliminated in urine when not needed by the body. Food must therefore supply it continuously. It belongs to a group of other water-soluble vitamins that are often present together and called B-complex. The other members of the vitamin B complex are riboflavin, niacin, pantothenic acid, biotin , pyridox-ine, folic acid, inositol, and vitamin B12 . Important sources of thiamin are vegetables, wholegrain products, and nuts. The best sources are yeasts and liver and pork meat. Some specific good food sources of thiamin include (per 1 cup serving or as indicated):

  • romaine lettuce (0.05 mg)
  • asparagus, boiled (0.22 mg)
  • spinach, boiled (0.17 mg)
  • tuna (0.57 mg per 4 oz-serving)
  • celery, raw (0.06 mg)
  • green peas, boiled (0.41 mg)
  • tomato (0.11 mg)
  • eggplant, cooked (0.08 mg)
  • brussels sprouts, boiled (0.17 mg per cup)
  • baked beans, canned with pork (0.6 mg)
  • cabbage, boiled (0.09 mg)
  • watermelon (0.12 mg)
  • red peppers, raw (0.06 mg per cup)
  • carrots, raw (0.12 mg)


AgeRecommended Dietary Allowance (mg)
Children 0–6 mos.0.2
Children 7–12 mos.0.3
Children 1–3 yrs.0.5
Children 4–8 yrs.0.6
Children 9–13 yrs.0.9
Boys 14–18 yrs.1.2
Girls 14–18 yrs.1.0
Men 19> yrs.1.2
Women 19> yrs.1.1
Pregnant women1.4
Breastfeeding women1.4
FoodThiamin (mg)
Sunflower seeds, ½ cup1.64
Beans, baked, canned with pork, 1 cup0.60
Tuna, 4 oz.0.57
Sesame seeds, ½ cup0.56
Beans, black, cooked, 1 cup0.42
Peas, green, boiled, 1 cup0.41
Beans, navy, cooked, 1 cup0.37
Peas, split, cooked, 1 cup0.37
Corn, cooked, 1 cup0.36
Lentils, cooked, 1 cup0.33
Beans, lima, cooked, 1 cup0.30
Beans, kidney, cooked, 1 cup0.28
Oats, whole grain, cooked, 1 packet0.26
Asparagus, boiled, 1 cup0.22
Brussels sprouts, boiled, 1 cup0.17
Spinach, boiled, 1 cup0.17
Squash, winter, baked, 1 cup0.17
Pineapple, 1 cup0.14
Carrots, raw, 1 cup0.12
Watermelon, 1 cup0.12
Oranges, 1 whole0.11
Tomato, 1 cup0.11
Broccoli, steamed, 1 cup0.09
Beans, green, boiled, 1 cup0.09
Cabbage, boiled, 1 cup0.09
Eggplant, cooked, 1 cup0.08
Squash, summer, cooked, 1 cup0.08
Kale, boiled, 1 cup0.07
Beans, baked, canned with pork, 1 cup0.06
Celery, raw, 1 cup0.06
Red peppers, raw, 1 cup0.06
Turnip greens, cooked, 1 cup0.06
Romaine lettuce, 1 cup0.05
Cauliflower, boiled, 1 cup0.05
mg = milligram 

(Illustration by GGS Information Services/Thomson Gale.)

  • summer squash, cooked (0.08 mg)
  • winter squash, baked (0.17 mg)
  • turnip greens, cooked (0.06 mg)
  • broccoli, steamed (0.09 mg)
  • green beans, boiled (0.09 mg)
  • corn, cooked (0.36 mg)
  • kale, boiled (0.07 mg per cup)
  • lentils, cooked (0.33 mg)
  • navy beans, cooked (0.37 mg)
  • lima beans, cooked (0.30 mg)
  • kidney beans, cooked (0.28 mg)
  • black beans, cooked (0.42 mg per cup)
  • oats, whole grain, cooked (0.26 mg per packet)
  • pineapple (0.14 mg)
  • oranges, each (0.11 mg)
  • cauliflower, boiled (0.05 mg)
  • split peas, cooked (0.37 mg)
  • sesame seeds (0.56 mg per 1/2 cup)
  • sunflower seeds (1.64 mg per 1/2 cup)

The Recommended Dietary Allowance (RDA) for thiamin is:

  • infants: (0-6 months): 0.2 mg
  • infants: (7-12 months): 0.3 mg
  • children (1-3 y): 0.5 mg
  • children (4-8 y): 0.6 mg
  • children (9-13 y): 0.9 mg
  • adolescents (14-18): males, 1.2 mg, females, 1.0 mg
  • adults: males, 1.2 mg, females, 1.1 mg
  • pregnancy: 1.4 mg
  • lactation: 1.4 mg

Thiamin in nutritional supplements can be found in multivitamins, B-complex vitamins, or can be sold individually. It may be labeled as thiamine hydrochloride or thiamine mononitrate and is available in a variety of forms including tablets, softgels, and lozenges, including chewable and liquid drops. Two fat-soluble forms of thiamin are also used. They are thiamin propyl disulfide and thiamin tetrahydrofurfuryl disulphide, and are sometimes used in treatment of thiamin deficiency because they follow a different route of absorption into the body than water-soluble thiamin.


Oral thiamin is generally nontoxic, but stomach upset can occur with excessive intake. Thiamin deficiency may result from a deficiency in the diet. People whose diet consists mainly of polished white rice are at risk, because polishing removes almost all of the vitamins. Alcoholics, who often substitute alcohol for food, are also at high risk of developing thiamin deficiency. Symptoms include fatigue, irritability, memory impairment, appetite loss, sleep disturbances, abdominal discomfort, and weight loss. Severe thiamin deficiency, called beriberi, is characterized by nerve, heart, and brain abnormalities. One form, called dry beriberi, causes nerve and muscle abnormalities. Symptoms include prickling felt in the toes, a burning


Amino acid— Organic (carbon-containing) molecules that serve as the building blocks of proteins.

Alzheimer’s disease— A progressive, incurable condition that destroys brain cells, gradually causing loss of intellectual abilities, such as memory, and extreme changes in personality and behavior.

Antibiotic— Drug that kills bacteria and other germs.

Antidepressants— Drugs used primarily to treat depression.

B-group vitamins— Group of eight water-soluble vitamins that are often present as a single, vitamin complex in many natural sources, such as rice, liver and yeast.

Carbohydrate— Any of a group of organic compounds that includes sugars, starches, celluloses, and gums and serves as a major energy source for the body.

Chemotherapy— Treatment of cancer with drugs.

Cofactor— A compound that is essential for the activity of an enzyme.

Crohn’s disease— Inflammatory disease that usually occurs in the last section of the small intestine (ileum), causing swelling in the intestines. It can also occur in the large intestine.

Diuretic— A substance that increases the flow of urine from the body.

Enzyme— A biological catalyst, meaning a substance that increases the speed of a chemical reaction without being changed in the overall process. Enzymes are proteins and vitally important to the regulation of the chemistry of cells and organisms.

Epilepsy— A disorder of the brain that results in recurrent, unprovoked seizures.

Fat-soluble vitamins— Vitamins, such as A, D, E and K that are found in fat or oil-containing foods, and which are stored in the liver, so that daily intake is not really essential.

Fibromyalgia— Widespread musculoskeletal pain and fatigue disorder for which the cause is still unknown.

Metabolism— The sum of the processes (reactions) by which a substance is assimilated and incorporated into the body or detoxified and excreted from the body.

Micronutrients— Nutrients needed by the body in small amounts. They include vitamins and minerals.

Multiple sclerosis— A chronic degenerative disease of the central nervous system in which gradual destruction of myelin occurs in patches throughout the brain or spinal cord, interfering with the nerve pathways and causing muscular weakness, loss of coordination and speech and visual disturbances.

Protein— Biological molecules that consist of strings of smaller units called amino acids, the ‘‘building blocks’’ of proteins. In proteins, amino acids are linked together in sequence as polypeptide chains that fold into compact shapes of various sizes. Proteins are required for the structure, function, and regulation of the body’s cells, tissues, and organs, and each protein has unique functions.

Recommended dietary allowance (RDA)— The levels of intake of essential nutrients judged on the basis of scientific knowledge to be adequate to meet the nutrient needs of healthy persons by the Food and Nutrition Board of the National Research Council/ National Academy of Sciences. The RDA is updated periodically to reflect new knowledge. It is popularly called the Recommended Daily Allowance.

Vitamin— A group of organic micronutrients, present in minute quantities in natural foodstuffs, that are essential to normal metabolism.

Water-soluble vitamins— Vitamins that are soluble in water and which include the B-complex group and vitamin C. Whatever water-soluble vitamins are not used by the body are eliminated in urine, which means that a continuous supply is needed in food.

sensation in the feet, very severe at night, pain, weakness, and wasting of leg muscles. The other form, wet beriberi, involves the heart and circulatory system and leads to heart abnormalities. Symptoms include a high output of blood from the heart, a fast heart rate, and dilation of blood vessels, making the skin warm and moist. Because the heart cannot maintain the high output, it becomes stressed and heart failure may occur, as well as abnormal fluid accumulation in the legs (edema) and in the lungs (congestion). If untreated, it leads to shock and death.


Thiamin is known to interact with the following medications and should not be taken at the same time:

  • Antiacids. These medications may lower thiamin levels in the body by decreasing absorption and increasing excretion or metabolism.
  • Tetracycline. Tetracyline is an antibiotic and thiamin taken either alone or in combination with other B vitamins interferes with its absorption by the body and action in the body.
  • Antidepressants. Thiamin supplements may improve the action of antidepressants such as nortriptyline, especially in elderly patients. Other medications in this class of drugs include desimpramine and imipramine.
  • Chemotherapy drugs. Laboratory studies suggest that thiamin may prevent the activity of chemotherapy drugs, but effects are not yet understood in people. Patients undergoing chemotherapy for cancer, especially people receiving fluorouracil-contain-ing drugs, are usually advised not take large doses of vitamin B1 supplements.
  • Diuretics. Diuretics, especially furosemide, which belongs to a class of drugs called loop diuretics, may reduce the levels of thiamin in the body.
  • Digoxin. Laboratory studies also suggest that digoxin, a drug used to treat heart conditions, may lower the ability of heart cells to absorb and use thiamin, especially if digoxin is combined with furosemide.
  • Scopolamine. Thiamin may help reduce some of the side effects associated with scopolamine, a drug used to treat motion sickness.

Thiamin can also interact with food substances. Foods and beverages that may inactivate thiamin include those containing sulfites and tea, coffee and decaffeinated coffee. Consumption of betel nuts may also reduce thiamin activity due to chemical inactiva-tion, and may lead to symptoms of thiamin deficiency. Tobacco use also decreases thiamin absorption and may lead to decreased levels in the body.


All forms of thiamin deficiency are treated with supplements. If severe deficiency results in a medical emergency, it is treated with high doses of thiamin for several days. When alcoholics must be fed intravenously, they are often given supplements as a preventive measure. Doses for conditions, such as severe beriberi or alcoholism, are administered by a health care practitioner in an appropriate clinical setting. The symptoms of beriberi may recur years after apparent recovery.


Brain abnormalities due to thiamin deficiency are complications that occur mainly in alcoholics. They may develop when a chronic thiamin deficiency is suddenly worsened by a rapid decrease in the thiamin levels by an alcoholic binge or by a sudden increase in thiamin requirements when a malnourished alcoholic is fed intravenously. Brain abnormalities may develop in two stages: an early stage (Korsakoff’s syndrome) and a later stage (Wernicke’s encephalopathy). Together, they are called the Wernicke-Korsakoff syndrome. Korsakoff’s syndrome causes memory loss, and Wernicke’s encephalopathy causes mental confusion, difficulty walking, and eye problems. If Wernicke’s encephalopathy is not treated, symptoms may lead to coma and even death. As for excessive thiamin intake complications, rare hypersensitivity/allergic reactions have occurred with supplementation.

Parental concerns

Parents should refrigerate fresh produce and keep milk and grains away from strong light because vitamins are easily destroyed and washed out during food preparation and storage. Vitamin supplements should also be stored at room temperature in a dry place.

Taking thiamin for a long period of time can result in an imbalance of other B-complex vitamins. This is why it is generally recommended to take a B-complex vitamin with thiamin. Because of the potential for side effects and interactions with medications, thiamin supplements should also be taken only under the supervision of a knowledgeable health care provider.



Berkson, B., Berkson, A. J. User’s Guide to the B-complex Vitamins. Laguna Beach, CA: Basic Health Publications, 2000.

Carpenter, K. Beriberi, White Rice, and Vitamin B: A Disease, a Cause, and a Cure. Berkeley, CA: University of California Press, 2000.

Challem, J., Brown, L. User’s Guide to Vitamins & Minerals. Laguna Beach, CA: Basic Health Publications, 2002.

Garrison, R., Somer, E. The Nutrition Desk Reference. New York, NY: McGraw-Hill, 1998.

Griffith, H. W. Minerals, Supplements & Vitamins: The Essential Guide. New York, NY: Perseus Books Group, 2000.

Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington, DC: National Academies Press, 2000.

Larson Duyff, R. ADA Complete Food and Nutrition Guide, 3rd ed. Chicago, IL: American Dietetic Association, 2006.

Lieberman, S., Pauling-Bruning, N. E. The Real Vitamin and Mineral Book. London, UK: Avery (Penguin Group), 2003.

Newstrom, H. Nutrients Catalog: Vitamins, Minerals, Amino Acids, Macronutrients—Beneficials Use, Helpers, Inhibitors, Food Sources, Intake Recommendations. Jefferson, NC: McFarland & Company, 1993.


American Dietetic Association (ADA). 120 South Riverside Plaza, Suite 2000, Chicago, IL 60606-6995. 1-800/877-1600. <>.

American Society for Nutrition (ASN). 9650 Rockville Pike, Bethesda, MD 20814. (301) 634-7050. <>.

U.S. Department of Agriculture, Food and Nutrition Information Center. National Agricultural Library, 10301 Baltimore Avenue, Room 105, Beltsville, MD 20705. (301) 504-5414. <>.

Monique Laberge, Ph.D.

The Zone diet seeZone diet


views updated May 11 2018



Thiamine, also known as vitamin B1, was the first of the water-soluble B-vitamin family to be discovered. It is an essential component of an enzyme, thiamine pyrophosphate, that is involved in metabolizing carbohydrates. Thiamine works closely with other B vitamins to assist in the utilization of proteins and fats as well, and helps mucous membranes and the heart to stay healthy. The brain relies on thiamine's role in the conversion of blood sugar (glucose) into biological energy to function properly. Thiamine is also involved in certain key metabolic reactions occurring in nervous tissue, the heart, in the formation of red blood cells, and in the maintenance of smooth and skeletal muscle.

General use

The recommended daily allowance (RDA) of thiamine is 0.3 mg for infants less than six months old, 0.4 mg for those from six months to one year old, 0.7 mg for children ages one to three years, 0.9 mg for those four to six years, and 1.0 mg for those seven to 10 years. Requirements vary slightly by gender after age 10. Males need 1.3 mg from 11 to 14 years, 1.5 mg from 15 to 50 years, and 1.2 mg when over age 50 years. Females require 1.1 mg from 11 to 50 years of age, and 1.0 mg if older than 50 years. The RDA is slightly higher for women who are pregnant (1.5 mg) or lactating (1.6 mg). Adults need a minimum of 1.0 mg of thiamine a day, but the requirement is increased by approximately 0.5 mg for each 1,000 calories of daily dietary intake over a 2,000-calorie base.

Thiamine has limited therapeutic use apart from supplements for people who are deficient or have significant risk factors for deficiency, such as alcoholism . High doses are used to treat some metabolic disorders, including certain enzyme deficiencies, Leigh's disease, and maple syrup urine disease. People suffering from diabetic neuropathy may sometimes benefit from additional thiamine. This supplementation should be taken only on the advice of a healthcare provider. Claims have been made that it can also help people with Alzheimer's disease, epilepsy, canker sores, depression, fatigue, fibromyalgia , and motion sickness . Improvement of these conditions based on supplementation with thiamine is unsubstantiated. Although a deficiency of thiamine may cause canker sores, taking extra amounts of the vitamin after they appear does not seem to help them heal.


Natural sources

While all plant and animal foods have thiamine, higher levels of thiamine are found in many nuts, seeds, brown rice, seafood, and whole-grain products. Sunflower seeds are a particularly good source. Grains are stripped of the B vitamin content during processing, but it is often added back to breads, cereals, and baked goods. Legumes, milk, beef liver, and pork are other foods with high vitamin B1 content. Thiamine is destroyed by prolonged high temperatures, but not by freezing. Food should be cooked in small amounts of water so that thiamine and other water-soluble vitamins don't leach out. Baking soda should not be added to vegetables, and fresh foods should be eaten to avoid sulfite preservatives. Both of these chemicals will break down the thiamine content found in foods. Drinking tea or alcohol with a meal will also drastically decrease the amount of thiamine that is absorbed by the body.

Supplemental sources

Thiamine is available in oral, intramuscular injectable, and intravenous formulations. Injectable formulas are usually preserved for persons who are severely thiamine deficient. Supplements should always be stored in a cool dry place, away from direct light, and out of the reach of children.


A deficiency of thiamine leads to a condition known as beriberi. Once common in sailors, it has become rare in the industrialized parts of the world except in cases of alcoholism and certain disease conditions. Beriberi is, however, frequently found in refugee camps and similar shelters for displaced persons. Infantile beriberi is presently the leading cause of death among the children of ethnic minority groups in southeast Asia. The syndrome typically causes poor appetite, abdominal pain , heart enlargement, constipation , weakness, swelling of limbs, muscle spasms, insomnia , and memory loss . Under treatment, the condition can resolve very quickly. Untreated beriberi will lead eventually to Wernicke-Korsakoff syndrome. These patients experience confusion, disorientation, inability to speak, gait difficulties, numbness or tingling of extremities, edema, nausea, vomiting , visual difficulties, and may progress to psychosis, coma, and death. Even in advanced states, this condition can be reversible if thiamine is given, nutritional status is improved, and use of alcohol is stopped.

Risk factors for deficiency

The leading risk factor for developing a deficiency of thiamine is alcoholism. Generally, alcoholics eat poorly, and therefore have a low dietary intake of thiamine and other vitamins to begin with. Alcohol also acts directly to destroy thiamine and increases the excretion of it. People with cirrhosis of the liver, malabsorption syndromes, diabetes, kidney disease, chronic infections , or hypermetabolic conditions also have increased susceptibility to thiamine deficiency. The elderly are more prone to poor nutritional status as well as difficulties with absorption, and may need a supplement. Others with nutritionally inadequate diets , or an increased need as a result of stress , illness, or surgery may benefit from additional vitamin B1 intake since utilization is higher under these conditions. Those who diet or fast frequently may also be at risk for low levels of thiamine. Use of tobacco products, or carbonate and citrate food additives can impair thiamine absorption. A shortage of vitamin B1 is likely to be accompanied by a shortage of other B vitamins, and possibly other nutrients as well. A supplement containing a balance of B complex and other vitamins is usually the best approach unless there is a specific indication for a higher dose of thiamine, or other individual vitamins.


Thiamine should not be taken by anyone with a known allergy to B vitamins, which occurs rarely.

Side effects

In very unusual circumstances, large doses of thiamine may cause rashes, itching , or swelling. These reactions are more common with intravenous injections than oral supplements. Most people do not experience any side effects from oral thiamine.


Oral contraceptives, antibiotics, sulfa drugs, and certain types of diuretics may lower thiamine levels in the body. Consult a health care professional about the advisability of supplementation. Taking this vitamin may also intensify the effects of neuromuscular blocking agents that are used during some surgical procedures. B vitamins are best absorbed as a complex, and magnesium also promotes the absorption of thiamine.



Bratman, Steven, and David Kroll. Natural Health Bible. Rocklin, CA: Prima Publishing, 1999.

Griffith, H. Winter. Vitamins, Herbs, Minerals & Supplements: The Complete Guide. Arizona: Fisher Books, 1998.

Jellin, Jeff, Forrest Batz, and Kathy Hitchens. Pharmacist's Letter/Prescriber's Letter Natural Medicines Comprehensive Database. California: Therapeutic Research Faculty, 1999.

Pressman, Alan H., and Sheila Buff. The Complete Idiot's Guide to Vitamins and Minerals. New York: Alpha Books, 1997.


McGready, Rose, Julie A. Simpson, Thein Cho, et al. "Postpartum Thiamine Deficiency in a Karen Displaced Population." American Journal of Clinical Nutrition 74 (December 2001): 808813.


American Society for Nutritional Sciences. <>.

Judith Turner

Rebecca J. Frey, PhD


views updated May 18 2018


B vitamins are complex, water-soluble organic chemicals, often containing heterocyclic ring systems (containing one or more atoms other than carbon atoms); they cannot be synthesized by humans and are, therefore, required nutrients. Each of these vitamins is converted by the body into a coenzyme. Coenzymes are cofactors essential to the catalytic activity of enzymes.

Thiamin is also known as vitamin B1. In the body it is converted to thiamin pyrophosphate (TPP), an essential coenzyme serving enzymes involved in the breakdown of nutrient molecules for energy. Thiamin deficiency in its severest form causes beriberi.

Thiamin is converted to TPP via the transfer of a pyrophosphate group to thiamin from adenosine triphosphate (ATP) .

In animals TPP-dependent decarboxylation reactions are essential to the production of energy needed for cell metabolism . In these reactions α -ketoacids are converted to acyl CoA molecules and carbon dioxide. The reactions (e.g., the conversion of pyruvate to acetyl CoA) are an important part of the breakdown of carbohydrates, and of the conversion of several classes of molecules (carbohydrates, fats, and proteins) to energy, carbon dioxide, and water in the citric acid cycle. In other organisms, in addition to its participation in the above reactions, TPP is a required coenzyme in alcohol fermentation, in the carbon fixation reactions of photosynthesis , and in the biosynthesis of the amino acids leucine and valine.

Major food sources of thiamin are fortified breads, cereals, pasta, whole grains (especially wheat germ), lean meats (especially pork and liver), fish, peanuts, dried beans, peas, and soybeans. Fruits and vegetables are not high in thiamin but are a significant source of thiamin if they are consumed in large enough amounts. The daily value (DV) of thiamin for adults is 1.5 milligrams (5.3 × 105 ounces). Thiamin deficiency virtually does not occur in North America. Because thiamin is water-soluble and easily removed from the body there is no known toxicity.

Beriberi has been found in people who eat polished rice (with husks discarded) and few other foods, as thiamin is in the husks of grains. Beriberi is associated with damage to the nervous system, brain, heart, and blood vessels. It is fatal if not treated with adequate amounts of thiamin. Lesser deficiencies of thiamin lead to weakness and fatigue. These lesser deficiencies respond rapidly to thiamin unless they are complicated by another condition, for example, alcoholism.

CASIMIR FUNK (18841967)

Beriberi, a fatal disease, was prevalent at the turn of the nineteenth century among groups who ate large quantities of polished rice. Casimir Funk correctly theorized that the discarded polishings contained some nutrient for disease prevention. Funk isolated this item and called it a "vitamine," combining vite, meaning life, and amine.

Valerie Borek

see also Coenzyme.

Vivienne A. Whitworth


Nelson, David L., and Cox, Michael M. (2000). Lehninger Principles of Biochemistry, 3rd edition. New York: Worth Publishers.

Internet Resources

"Thiamin." Yahoo Health. Available from <>.

"Thiamin Deficiency and Dependency." Merck Manual of Diagnosis and Therapy. Available from <>.


views updated May 11 2018


Like all the water-soluble B vitamins, thiamine functions as a coenzyme. Thiamine works primarily in the metabolism (processing) of carbohydrates, fats and proteins. It also helps to produce ribose, an important sugar needed by all body cells for the production of nucleic acids.

Thiamine is neither synthesized (blended or created artificially) by the body's intestinal bacteria nor stored in fat tissues. Because the body neither produces nor stores thiamine, a daily dietary source is needed. Without such a source, both humans and most animals soon develop some form of deficiency disease. In humans, the disease is called beriberi. Beriberi is a serious and disabling disease characterized by polyneuritis (an inflammation of nerves in the arms and legs.) It was the search for a cure for beriberi that led to the discovery of thiamine.

Beriberi Research

In the 1880s most physicians were certain that beriberi was caused by some sort of toxic (poisonous) bacteria. The disease was particularly widespread in Far Eastern countries where rice was a dietary staple. Because of this, the bacteria was suspected to be in rice. In 1886 a commission was sent to the Dutch East Indies (now Indonesia) to try and locate the causative organism. The commission failed to find the organism, but one of its members, Christiaan Eijkman (1858-1930) stayed behind to continue his experiments.

Between 1890 and 1897 Eijkman began reporting that chickens fed a diet high in polished rice developed symptoms similar to those of his beriberi patients. Even more important, Eijkman reported that adding rice hulls to the diet quickly effected a cure. A colleague named Gerrit Grijns found that other foodsincluding green peas and meatcould also prevent beriberi. In 1901 Grijns correctly deduced that beriberi was not the result of a bacteria based on his experiments which proved that certain natural foodstuffs contained an anti-beriberi factor.

Roughly a decade later Casimir Funk, a Polish-born biochemist, was inspired by reading the reports of Grijns and Eijkman. Funk began searching for the elusive anti-beriberi factor in rice hulls. He managed to isolate an active substance and was briefly elated. Unfortunately, the substance (which later proved to be niacin) had only minimal effect on beriberi. Funk discarded it and went on with his research.

In 1926 two other biochemists isolated a crystalline material that could actually cure polyneuritis in birds. The discovery was made by P. Jansen and W.P. Donath, working in the same laboratory in the Dutch East Indies originally used by Eijkman and Grijns. The two researchers called the substance they found aneurine. Too little of the substance could be isolated, however, to make identification certain.

A Rare Substance

In the 1930s scientists made important discoveries that would allow them to synthesize the substance. In 1932 German chemist Adolf Windaus (1876-1959) was able to isolate a sulfur atom in a molecule of another substance. This proved to be a crucial step in determining the structure of the elusive compound. In 1934 American chemist Robert Runnels Williams (1886-1965), isolated one-third of an ounce of the active crystalline material from almost a ton of rice hulls. His procedure used highly advanced laboratory techniques, but was too expensive to be used for mass production. Because the vitamin proved to contain a sulfur molecule (of the thio group) and an amine, the substance was named thiamine. Two years later, Williams and his colleagues successfully synthesized the substance.

Today thiamine is a regular component of many multivitamins and continues its role of preventing this ancient disease.


views updated Jun 08 2018

thi·a·mine / ˈ[unvoicedth]īəmin; -mēn/ (also thi·a·min / -min/ ) • n. Biochem. a vitamin of the B complex, found in unrefined grains, beans, and liver, a deficiency of which causes beriberi. It is a sulfur-containing derivative of thiazole and pyrimidine. Also called vitamin B1.


views updated May 14 2018

thiamine Vitamin B1 (see VITAMIN). It contributes to the formation of the important coenzyme thiamine pyrophosphate, which is involved in the oxidative decarboxylation of alpha-keto acids and transketolase reactions. A deficiency of this compound in humans causes beriberi.


views updated May 23 2018

thiamine Vitamin B1 of the B complex, required for carbohydrate metabolism. Its deficiency causes beriberi. Thiamine is found in grains, nuts, liver, yeast, and legumes.


views updated May 18 2018

thiamine Vitamin B1. It contributes to the formation of the important coenzyme thiamine pyrophosphate which is involved in the oxidative decarboxylation of alpha-keto acids and transketolase reactions.


views updated May 29 2018

thiamin (vitamin B1) (th'y-ă-min) n. see vitamin B.


views updated Jun 08 2018

thiamin(e) See vitamin B complex.