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Vitamin B1 - Thiamine

Thiamine is an important member of the B group.

The functions of vitamin B1 (thiamine)

Vitamin B1 is a powerful antioxidant that is necessary for regulating and normalizing the conversion of glucose into energy. It provides the neurons (nerve cells) with important building blocks needed for energy production and increases blood flow in memory tissue.

Vitamin B1 is important for:

The body requires higher amounts of B1 when increased calories are consumed, particularly starches and sugars. Thiamine is easily destroyed by: air, water, coffee, alcohol, estrogen and food additives.

Increased amounts of vitamin B1 may be needed with the use of antibiotics, sulfa drugs, and oral contraceptives.

The symptoms and signs of vitamin B1 deficiency

In the most severe form, vitamin B1 deficiency results in beri-beri. This is relatively uncommon except in alcoholics.

A less severe deficiency can result in symptoms including:

It is interesting to note that 30% of those entering psychiatric wards are deficient in thiamine.

Food sources of vitamin B1

The foods that contain vitamin B1 include: brewer's or nutritional yeast, brown rice, egg yolks, fish, legumes, liver, nuts, peas, poultry, and rice bran.

Who might benefit from extra thiamine?

Several groups of people are at risk of a vitamin B1 deficiency. They include:

How much do we need?

Generally a daily dosage of 50 to 100 mg is adequate. For those suffering from age related mental decline or Alzheimer's disease, the therapeutic dose is 3-8 grams daily (with the whole B complex being taken at some other point during the day).

Vitamin B1 toxicity is very rare and it is one of the safest of the vitamins. However, excessive vitamin B1 can deplete other B vitamins and disrupt insulin and thyroid production.

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Bland, J. 1996, Contemporary Nutrition. J & B Associates.

Davies, S. and A. Stewart., 1997, Nutritional Medicine. Pan.

Holden, S., Hudson, K., Tilman, J. & D. Wolf, 2003, The Ultimate Guide to Health from Nature. Asrolog Publication.

Pressman, A. and S. Buff, 2000, The Complete Idiot's Guide to Vitamins and Minerals. (2nd Ed.) Alpha Books.

Soothill, R. 1996, The Choice Guide to Vitamins and Minerals. A Choice Book Publication.

Sullivan, K. 2002, Vitamins and Minerals: A Practical Approach to a Health Diet and Safe Supplementation. Harper Collins.

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Thiamin was one of the first vitamins to be recognized, but it was not until the late nineteenth and early twentieth centuries that dietary factors were thought to play a role. In the Far East the consumption of polished (refined) rice often led to vitamin B1 deficiencies, as the discarded rice bran contained most of the vitamin B1.

In the Second World War, many of the European prisoners of war held in the Far East developed a vitamin B1 deficiency because of the poor diet they were fed. The term beri-beri (Singhalese for 'extreme weakness') was used to describe the disease that resulted because of a vitamin B1 deficiency.