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.
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