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Vitamin B1

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Other Terms:

Thiamine | Thiamin | Aneurine


Water soluble, which means any excess is readily excreted in urine.  As very little of it is stored, the body can be depleted of thiamine within as short a time as 2 weeks.

On this Page: What is Vitamin B1 · Benefits · Deficiency Signs · Foods · Supplements · RDA · Toxicity | Overdose

What is Vitamin B1 ?
Vitamin B1 is also known as thiamine or thiamin. It is one of the B Complex vitamins, and needs to be taken together with the other B vitamins.  It is most well known for its role in the prevention and cure of beriberi.

It is very unstable and easily damaged by heat, acidity and additives such as sulfites and nitrites.  Long refrigeration of food, for example over one or two years, often result in substantial loss of 30-90% of the thiamine in it. Grains that are heat-processed for use in cereals can lose more than half their thiamine content.

How Vitamin B1 Benefits Health
The B vitamins play an important role in maintaining the muscle tone in the gastrointestinal tract, as well as healthy skin, eyes, hair, liver, heart, and nerves.  These vitamins, especially thiamine, are co-enzymes that are vital for energy production and many essential chemical processes in the body.

This list summarizes the main ways thiamine benefits our health.

:: Vitamin B1 Benefits & Functions
1. supports production of hydrochloric acid for the digestive system
2. plays a critical role in carbohydrate metabolism and energy production
3. optimizes brain function and learning capacity
4. promotes mental alertness and memory
5. fights depression
6. may be associated with reduced risk of cataracts, based on preliminary studies
7. may help widen arteries that have narrowed, and slow the development of atherosclerosis
8. needed for blood cell formation
9. crucial for a healthy nervous system
10. needed for production of acetylcholine, a neurotransmitter (messaging molecule) that coordinates activity between nerves and muscles
11. used by the nervous system to ensure normal muscle tone of the heart, stomach and intestines


Vitamin B1 Deficiency Symptoms and Causes
Vitamin B1 deficiency symptoms might arise from a deficient diet or be due to poor absorption caused by an underlying stomach or intestinal disorder.

Use of antibiotics, antacids, oral contraceptives, sulfa drugs, and smoking may also lead to lower levels of thiamine in the body. A high-carbohydrate diet increases the need for thiamine to process it.

Heavy tea or coffee drinking, as well as diarrhea, causes water and water soluble vitamins to be lost from the body.  In such cases, up to 10 times the normal amount of thiamine is needed.

Thiamine deficiency is most commonly seen in those who consume a lot of alcohol.  Alcohol affects uptake of thiamine so that someone who drinks heavily but who has a well-balanced diet otherwise would still be short, as most of the thiamine in the food is not absorbed.  He would need between 10 to 100 times the normal intake, to achieve the level needed.

The common vitamin B1 deficiency symptoms are listed here, including the diverse symptoms of beriberi which is the most well-known disease caused by severe chronic thiamine deficiency.

:: Vitamin B1 Deficiency Symptoms
1. disruption of energy production, resulting in muscular weakness or excessive fatigue
2. lack of energy that leads to appetite and weight loss
3. “pins and needles” or tingling sensations or vague aches and pains
4. loss of sensation (numbness) in the hands, and especially the legs
5. severe deficiency can cause nerve damage with loss of muscle function or paralysis of the lower leg
6. heart abnormalities such as palpitations or enlarged heart, and in severe cases even heart failure
7. lung congestion and difficulty in breathing due to lack of muscle tone
8. gastrointestinal disorders like indigestion or constipation arising from loss of muscle tone
9. lower thiamine levels have been found in patients with Crohn's disease
10. contributes to recurrent canker sores (aphthous or oral ulcers)
11. stunted growth
12. forgetfulness or mental confusion
13. nervous irritability or mental depression
14. vague fears or feelings of persecution
15. severe deficiency can lead to brain damage and a form of dementia, Wernicke-Korsakoff syndrome, that is mainly characterized by vision changes, ataxia (lack of muscle coordination that can affect movement, speech, and swallowing) and impaired memory and learning


Vitamin B1 Foods
Thiamine rich foods · mushrooms · sunflower seeds · tuna · vegetables such as asparagus, broccoli, Brussels sprouts, romaine lettuce, spinach, tomatoes.

Other foods high in thiamin · animal liver · brewer's yeast · egg yolk · fish · lean meat (pork, poultry, beef) · nuts · pulses like chickpeas, dhal, lentils, soybeans · raw rice bran · vegetables such as beans, beets, cauliflower, eggplant, green peas · wheat germ · whole grains and cereals such as unpolished rice and oatmeal.


Vitamin B1 Supplements
Taking vitamins and minerals in their correct balance is vital to the proper functioning of all vitamins.  They work synergistically, which means that the effectiveness of any one nutrient requires or is enhanced, sometimes dramatically, by the presence of certain other nutrients.

For this reason, if you are looking to take supplements for maintenance of optimal health, the recommended approach is to take a multi-vitamin that has the proper balance of all the necessary nutrients your body needs.

For a list of reputable top ranked vitamin and mineral supplements chosen in an independent supplement review, see Best Multivitamin Supplements. Many of these are manufactured to pharmaceutical or nutraceutical GMP compliance, which is the highest multivitamin standard possible.

Keep in mind, however, that while vitamin supplements are useful to plug nutritional gaps that are almost inevitable in modern diets, and to ensure we get optimal doses of nutrients, they are no substitute for a good diet. Instead, use them to complement a healthy diet and lifestyle.


Vitamin B1 RDA (Recommended Dietary Allowance)
The Food & Nutrition Board of the Institute of Medicine, National Academy of Sciences, in their 1997-2001 collaboration between the US and Canada, set the daily Adequate Intake (AI) of Vitamin B1 as follows.

Life Stage | Gender Vitamin B1 Dosage | Day
Infants 0-6 mths 0.2* mg
Infants 7-12 mths 0.3* mg
Children 1-3 yrs 0.5 mg
Children 4-8 yrs 0.6 mg
Girls 9-13 Yrs 0.9 mg
Boys 9-13 Yrs 0.9 mg
Females 14-18 Yrs 1.0 mg
Males 14-18 Yrs 1.2 mg
Females 19-50 Yrs 1.1 mg
Males 19-50 Yrs 1.2 mg
Females older than 50 Yrs 1.1 mg
Males older than 50 Yrs 1.2 mg
Pregnant Women 14-18 Yrs 1.4 mg
Pregnant Women 19-50 Yrs 1.4 mg
Lactating Mothers 14-18 Yrs 1.4 mg
Lactating Mothers 19-50 Yrs 1.4 mg

These dosages are the minimum required per day to ward off deficiency. In therapeutic use of this nutrient, dosage is increased as necessary for the ailment, keeping in mind Vitamin B1 toxicity levels.


1 µg = 1 mcg = 1 microgram = 1/1,000,000 of a gram
1 mg = 1 milligram = 1/1,000 of a gram

* Indicates AI figures based on Dietary Reference Intake (DRI) figures


Vitamin B1 Overdose Symptoms, Toxicity Level & Side Effects
No thiamine overdose symptoms have been reported even at high thiamine dosage levels, except for rare cases of allergic reactions.

In its 1998 recommendations, the Food & Nutrition Board of the Institute of Medicine, National Academy of Sciences, did not set a Tolerable Upper Intake Level (UL) for it due to the lack of data on adverse effects.

In the absence of guidelines, do not take excessive amounts above the RDA.  Avoid thiamine overdose, except for therapeutic dosages under a healthcare professional.

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1. Institute of Medicine, Food and Nutrition Board. Dietary reference intakes for thiamin, riboflavin, niacin, vitamin B6, folate, vitamin B12, pantothenic acid, biotin, and choline. Washington, DC: National Academy Press; 1998.

2. U.S. National Libary of Medicine [NLM] & National Institutes of Health [NIH]: MedlinePlus. NLM-NIH home page. <http://www.nlm.nih.gov/medlineplus>. Use the built-in search function to find specific data. Accessed 2009 March – June.

3. The George Mateljan Foundation: The world's healthiest foods [WHFoods]. WHFoods home page. <http://www.whfoods.com>. Accessed 2009 March – June.

4. Balch JF, Balch PA. Prescription for nutritional healing: A practical A-Z reference to drug-free remedies using vitamins, minerals, herbs & food supplements. Garden City Park, New York: Avery Publishing; 1990.

5. Ulene A. Dr. Art Ulene's complete guide to vitamins, minerals and herbs. New York, NY: Avery Publishing; 2000.

6. Nolan A, McIntosh WB, Allam BF, Lamey PJ. Recurrent aphthous ulceration: vitamin B1, B2 and B6 status and response to replacement therapy. J Oral Pathol Med. 1991 Sep;20(8):389-91. [PubMed abstract]

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