What is Vitamin B1?
Vitamin B1, also called thiamine or thiamin, is one of the 8 vitamins
from the B Family. All B vitamins help the body convert food (carbohydrates)
into fuel (glucose), which is used to produce energy. These B vitamins, often
referred to as B complex vitamins, also help the body metabolize fats and
protein. B complex vitamins are needed for healthy skin, hair, eyes, and liver.
They also help the nervous system function properly, and are needed for good
brain function.
All B vitamins are water-soluble, meaning that the body does not store
them.
Like other B complex vitamins, thiamine is sometimes called an
"anti-stress" vitamin because it may strengthen the immune system and
improve the body's ability to withstand stressful conditions. It is named B1
because it was the first B vitamin discovered. Isolated and characterized in
the 1930s, thiamin was one of the first organic compounds to be recognized as a
vitamin. Thiamin occurs in the human body as free thiamin and as various phosphorylated
forms: thiamin monophosphate (TMP), thiamin triphosphate (TTP), and thiamin
pyrophosphate (TPP), which is also known as thiamin diphosphate.
It’s rare to be deficient in thiamine, although alcoholics, people with
Crohn' s disease, anorexia, and those undergoing kidney dialysis may be
deficient. Symptoms of thiamine deficiency are fatigue, irritability,
depression and abdominal discomfort. People with thiamine deficiency also have
trouble digesting carbohydrates. That allows a substance called pyruvic acid to
build up in their bloodstream, causing a loss of mental alertness, difficulty
breathing, and heart damage, a disease known as beriberi.
Wernicke-Korsakoff
syndrome
Wernicke-Korsakoff
syndrome is a two-stage brain disorder caused by a deficiency of thiamine
(vitamin B-1). Thiamine helps brain cells produce energy from sugar. When
levels of the vitamin are too low, cells are unable to generate enough energy
to function properly.
Wernicke
encephalopathy is the first, acute phase and Korsakoff psychosis is the
long-lasting, chronic stage. The most common cause is alcoholism, but the
syndrome can also be associated with AIDS, cancers that have spread through the
body, very high levels of thyroid hormone, and certain other conditions.
It involves two
separate phases:
- Wernicke encephalopathy is the first, acute phase.
- Korsakoff psychosis is the long-lasting, chronic stage.
Symptoms of
Wernicke-Korsakoff syndrome include:
- Confusion, permanent gaps in memory and
problems with learning new information.
- Individuals may have a tendency to
“confabulate” or “make up” information they can’t remember. They are not
necessarily “lying,” but may actually believe the invented explanation.
- Unsteadiness, muscle weakness and lack
of coordination.
Link to Alzheimer’s
Since lack of thiamine can cause dementia in Wernicke-Korsakoff syndrome,
some researchers have speculated that thiamine might help fighting Alzheimer's
disease. This assumption came from the fact that Wernicke-Korsakoff syndrome progress can be stopped by a timely
injection of a large dose of thiamine.
Also, recent
research suggests that APOE-e4 – a variant of a gene that produces the protein
apolipoprotein E – may be associated with a higher risk of Wernicke-Korsakoff
in individuals who drink heavily. APOE-e4 is also linked to a higher risk of
developing Alzheimer’s.
Research
A case-control study, performed in Aker University Hospital, Oslo,
Norway (2004), in 38 elderly women found that blood levels of thiamin, thiamin
pyrophosphate (TPP), and thiamin monophosphate (TMP) were lower in those with
dementia of Alzheimer's type (DAT) compared to the those in the control group.
This and other studies have confirmed the hypothesis on the possible
thiamin deficiency in Alzheimer’s patients. However, the reverse claim that thiamin
supplements might positively affect the Alzheimer’s patients, slowing down or
reversing the development of disease, has not been fully confirmed so far.
Actually, the results are mixed: some studies show slight therapeutic effect for
the AD patients, other demonstrate no effect at all. Some examples:
- One of the first
studies on the subject was a
study by researcher RH Haas in 1988, which suggested that a high dose of
thiamine indeed helps to restore memory and cognitive function in the
early stages of Alzheimer's type dementia patients.
- A double-blind, placebo-controlled
study (1993) of 15 patients (ten completed the study) reported no
beneficial effect of 3 grams of thiamin/day on cognitive decline over a
12-month period.
- 1992 study by Cornell University Medical College, Burke Medical
Research Institute, White Plains, have concluded that treatment with large
doses of thiamin has not been found beneficial, but the data was not
totally negative. Further studies of thiamin-dependent mechanisms in DAT were
recommended.
- In the 1993 study, performed in Medical College of Georgia, Augusta,
there were examined the effects of 3 to 8 g/day thiamine administered
orally to the AD patients. The results suggested that thiamine at these
pharmacologic dosages may have a mild beneficial effect in dementia of
Alzheimer's type.
- Mild beneficial
effect in patients with Alzheimer's disease was reported after 12 weeks of
treatment with 100 milligrams/day of a thiamin derivative (thiamin
tetrahydrofurfuryl disulfide), reported by the scientists from Hiroshima University School of Medicine,
Japan. The improvement could be observed not only in the patients’
emotional or other mental symptoms but also in intellectual function. However,
only mildly impaired subjects showed cognitive improvement.
- Another recent
systematic review of randomized, double- blind, placebo-controlled trials
of thiamin in patients with DAT found no evidence that thiamin was a
useful treatment for the symptoms of Alzheimer's disease (Hospital de la Santa Creu i Sant Pau, Barcelona,
Catalunya, Spain, 2001).
So, presently, there is only slight and inconsistent evidence that thiamin supplements may be of certain benefit in Alzheimer's disease. In any case, the vitamin B1 is known to help maintaining a positive mental attitude; enhancing learning abilities; increasing energy; fighting stress; and preventing memory loss. So, it is a good and generally safe to take natural supplement.
Dietary
Sources
Most foods contain small amounts of thiamine. Large amounts can be found
in pork and organ meats. Other good dietary sources of thiamine include
whole-grain or enriched cereals and rice, legumes, wheat germ, bran, brewer's
yeast, and blackstrap molasses.
Available
Forms
Vitamin B1 can be found in multivitamins (including chewable and liquid
drops), B complex vitamins, or if 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?
Daily recommendations for dietary vitamin B1 according to the National
Academy of Sciences are listed below.
- Men 19
years and older: 1.2 mg (RDA)
- Women 19
years and older: 1.1 mg (RDA)
A daily dose of 50 - 100 mg is often taken as a supplement. Thiamine
appears safe even these doses but you should talk to your doctor before taking
a large amount.
Precautions
Because of the potential for side effects and interactions with
medications, you should take dietary supplements only under the supervision of
a knowledgeable health care provider. Thiamine is generally safe. Very high
doses may cause stomach upset. Taking any one of the B vitamins for a long
period of time can result in an imbalance of other important B vitamins. For
this reason, you may want to take a B complex vitamin, which includes all the B
vitamins.
Possible
Interactions
If you are currently being treated with any of the following medications,
you should not use vitamin B1 without first talking to your health care
provider.
- Digoxin -- 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 (Lasix, a
loop diuretic).
- Diuretics (water pills) --
Diuretics, particularly furosemide (Lasix), which belongs to a class
called loop diuretics, may reduce levels of vitamin B1 in the body. It's
possible that other diuretics may have the same effect. If you take a
diuretic, ask your doctor if you need a thiamine supplement.
- Phenytoin (Dilantin) -- Some evidence
suggests that some people taking phenytoin have lower levels of thiamine
in their blood, and that may contribute to the side effects of the drug.
However, that is not true of all people who take phenytoin. If you take
phenytoin, ask your doctor if you need a thiamine supplement.
Sources and Additional Information:
