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:

detoxification;
heart function;
improving the mental state;
promoting growth;
toning muscles of the intestines, stomach, and heart; and
the overall health of the nervous system.

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:

fatigue,
depression,
constipation and other gastrointestinal disturbances,
edema,
enlarged liver,
forgetfulness,
loss of appetite,
atrophy of muscle tissue, and
numbness of the legs or tingling sensations.

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:

those with a moderate to high alcohol consumption,
the elderly,
those who pass large volumes of urine, such as diabetics,
those on diuretic medication (water tablets) or digoxin (a drug used in heart failure),
those recovering form heart failure,
those who consume a lot of refined carbohydrates or junk food,
psychiatric patients, particularly those suffering from depression and anxiety,
women on the contraceptive pill or estrogen replacement therapy,
those with liver or thyroid disease,
people suffering from or recovering from infections, and
those suffering from recurrent vomiting, such as in pregnancy, those with stomach disease and those with cancer.

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.

References

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.