Vitamin B1, also called thiamine, is one of eight water-soluble B vitamins.
All B vitamins help the body to convert carbohydrates into glucose (sugar),
which is "burned" to produce energy. These B vitamins, often referred to as B
complex vitamins, are essential in the breakdown of fats and protein. B complex
vitamins also play an important role in maintaining muscle tone along the wall
of the digestive tract and promoting the health of the nervous system, skin,
hair, eyes, mouth, and liver.
Similar to some other B complex vitamins, thiamine is considered an
"anti-stress" vitamin because it is believed to enhance the activity of the
immune system and improve the body's ability to withstand stressful conditions.
Thiamine is found in both plants and animals and plays a crucial role in
certain metabolic reactions, particularly, as mentioned, the conversion of
carbohydrates (starches) into energy. For example, thiamine is essential during
exercise, when energy expenditure is high.
Thiamine deficiency is rare, but tends to occur in people who get most of
their calories from sugar or alcohol. Individuals with thiamine deficiency have
difficulty digesting carbohydrates. As a result, a substance called pyruvic acid
builds up in the bloodstream, causing a loss of mental alertness, difficulty
breathing, and heart damage. In general, thiamine supplements are primarily used
to treat this deficiency known as beriberi.
The most important use of thiamine is in the
treatment of beriberi, a condition caused by a deficiency of thiamine in the
diet. Symptoms include swelling, tingling or burning sensation in the hands and
feet, confusion, difficulty breathing (from fluid in the lungs), and
uncontrolled eye movements (called nystagmus).
Wernicke-Korsakoff syndrome is a
brain disorder caused by thiamine deficiency. Replacing thiamine alleviates the
symptoms of this syndrome. Wernicke-Korsakoff is actually two disorders in one:
(1) Wernicke's disease involves damage to nerves in the central and peripheral
nervous systems and is generally caused by malnutrition (particularly a lack of
thiamine) associated with habitual alcohol abuse, and (2) Korsakoff syndrome is
characterized by memory impairment with various symptoms of nerve damage. High
doses of thiamine can improve muscle incoordination and confusion associated
with this disease, but only rarely improves the memory loss.
Dietary and supplemental vitamin B2, along with
other nutrients, is important for normal vision and prevention of cataracts
(damage to the lens of the eye which can lead to cloudy vision). In fact, people
with plenty of protein and vitamins A, B1, B2, and B3 (niacin) in their diet are
less likely to develop cataracts. Plus, taking additional supplements of
vitamins C, E, and B complex (particularly the B1, B2, B9 [folic acid], and B12
[cobalamin] in the complex ) may further protect the lens of your eyes from
It is especially important for people who have sustained
serious burns to obtain adequate amounts of nutrients in their daily diet. When
skin is burned, a substantial percentage of micronutrients may be lost. This
increases the risk for infection, slows the healing process, prolongs the
hospital stay, and even increases the risk of death. Although it is unclear
which micronutrients are most beneficial for people with burns, many studies
suggest that a multivitamin including the B complex vitamins may aid in the
Thiamine may be related to heart failure in two
ways. First, low levels of thiamine may contribute to the development of
congestive heart failure (CHF). On the flip side, people with severe heart
failure can lose a significant amount of weight including muscle mass (called
wasting or cachexia) and become deficient in many nutrients. It is not known
whether taking thiamine supplements would have any bearing on the development or
progression of CHF and cachexia. Eating a balanced diet, including thiamine, and
avoiding things that deplete this nutrient, such as high amounts of sugar and
alcohol, seems prudent, particularly for those at the early stages of CHF.
Some scientists have speculated that thiamine may have
some benefit in treating Alzheimer's disease. This theory is based on the
effects that this nutrient has on the brain and the symptoms that people develop
when deficient in thiamine. The studies on this subject to date are limited in
number and inconclusive, however. Much more research would be needed before
anything could be said regarding a possible use for thiamine in treating
Limited quantities of thiamine can be found in most foods, but large amounts
of this vitamin can be found in pork and organ meats. Other good dietary sources
of thiamine include whole-grain or enriched cereals and rice, wheat germ, bran,
brewer's yeast, and blackstrap molasses.
Vitamin B1 can be found in multivitamins (including children's chewable and
liquid drops), B complex vitamins, or can be sold individually. It is available
in a variety of forms including tablets, softgels, and lozenges. It may also be
labeled as thiamine hydrochloride or thiamine mononitrate.
|How to Take It|
As with all medications and supplements, check with a healthcare provider
before giving vitamin B1 supplements to a child.
Daily recommendations for dietary vitamin B1 are listed below.
- Newborns to 6 months: 0.2 mg (adequate intake)
- Infants 7 months to 1 year: 0.3 mg (adequate intake)
- Children 1 to 3 years: 0.5 mg (RDA)
- Children 4 to 8 years: 0.6 mg (RDA)
- Children 9 to 13 years: 0.9 mg (RDA)
- Males 14 to 18 years: 1.2 mg (RDA)
- Females 14 to 18 years: 1 mg (RDA)
- Males 19 years and older: 1.2 mg (RDA)
- Females 19 years and older: 1.1 mg (RDA)
- Pregnant females: 1.4 mg (RDA)
- Breastfeeding females: 1.5 mg (RDA)
Doses for conditions like beriberi and Wernicke-Korsakoff syndrome are
decided by a healthcare practitioner in an appropriate clinical setting. For
Wernicke-Korsakoff syndrome, thiamine is administered by venous injection.
Because of the potential for side effects and interactions with medications,
dietary supplements should be taken only under the supervision of a
knowledgeable healthcare provider.
Oral vitamin B1 is generally nontoxic. Stomach upset can occur at very high
doses (much higher than the recommended daily amount).
Taking any one of the B complex vitamins for a long period of time can result
in an imbalance of other important B vitamins. For this reason, it is generally
important to take a B complex vitamin with any single B
If you are currently being treated with any of the following medications, you
should not use vitamin B1 without first talking to your healthcare provider.
Vitamin B1 should not be taken at
the same time as the antibiotic tetracycline because it interferes with the
absorption and effectiveness of this medication. Vitamin B1 either alone or in
combination with other B vitamins should be taken at different times from
tetracycline. (All vitamin B complex supplements act in this way and should
therefore be taken at different times from tetracycline.)
Antidepressant Medications, Tricylic
Taking vitamin B1
supplements may improve treatment with antidepressants such as nortriptyline,
especially in elderly patients. Other medications in this class of
antidepressants include desimpramine and imipramine.
Although the significance is not entirely clear,
laboratory studies suggest that thiamine may inhibit the anti-cancer activity of
chemotherapy agents. How this will ultimately prove relevant to people is not
known. However, it may be wise for people undergoing chemotherapy for cancer to
not take large doses of vitamin B1 supplements.
Laboratory studies suggest that digoxin (a medication
used to treat heart conditions) may reduce the ability of heart cells to absorb
and use vitamin B1; this may be particularly true when digoxin is combined with
furosemide (a loop diuretic).
Diuretics (particularly furosemide, which belongs to
a class called loop diuretics) may reduce the levels of vitamin B1 in the body.
In addition, similar to digoxin, furosemide may diminish the heart's ability to
absorb and utilize vitamin B1, especially when these two medications are
Vitamin B1 may help reduce some of the side
effects associated with scopolamine, a medication commonly used to treat motion
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|Review Date: April 2002|
|Reviewed By: Participants in the review process include: Ruth DeBusk, RD, PhD, Editor,
Nutrition in Complementary Care, Tallahassee, FL; Jacqueline A. Hart, MD,
Department of Internal Medicine, Newton-Wellesley Hospital, Harvard University
and Senior Medical Editor Integrative Medicine, Boston, MA; Gary Kracoff, RPh
(Pediatric Dosing section February 2001), Johnson Drugs, Natick, Ma; Steven
Ottariono, RPh (Pediatric Dosing section February 2001), Veteran's
Administrative Hospital, Londonderry, NH. All interaction sections have also
been reviewed by a team of experts including Joseph Lamb, MD (July 2000), The
Integrative Medicine Works, Alexandria, VA;Enrico Liva, ND, RPh (August 2000),
Vital Nutrients, Middletown, CT; Brian T Sanderoff, PD, BS in Pharmacy (March
2000), Clinical Assistant Professor, University of Maryland School of Pharmacy;
President, Your Prescription for Health, Owings Mills, MD; Ira Zunin, MD, MPH,
MBA (July 2000), President and Chairman, Hawaii State Consortium for Integrative
Medicine, Honolulu, HI.|
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