Alternate Names : Thiamine
Thiamine, also known as Vitamin B1, is a water-soluble vitamin. It was the
first vitamin to be discovered. Thiamine is one of eight members of the
vitamin B complex. The complex also includes:
Because thiamine is water-soluble, any extra is passed out
of the body in the urine. Thiamine is needed each day to maintain health.
Daily needs for thiamine are based on the amount of calories
taken in each day. The recommended daily allowances, called RDAs, for
thiamine are based on 0.5 milligram (mg) for every 1,000 calories
consumed. Based on the recommended calorie intake for men and
women at certain age levels, the RDAs for thiamine are:
men from 15 to 50 years = 1.5 mg
men over 50 years = 1.2 mg
women from 11 to 50 years = 1.1 mg
women over 50 years = 1.0 mg
pregnant women = 1.5 mg
breastfeeding women = 1.6 mg
Thiamine is common in foods. A balanced diet based on the
Food Guide Pyramid
should provide enough thiamine daily.
A disease called beriberi, which affects the nerves and
heart, is caused by a lack of thiamine in the diet. This is extremely
rare in the United States, because enriched grain products are so common.
Before grains were enriched, it was much more common.
Mild thiamine deficiencies are more common. Exceptions may be found
with chronic alcoholism,
fasting, the elderly, and chronic dieting. Symptoms usually show up in the
nerves, stomach, and heart. Early warning signs include:
fatigue and weakness
loss of appetite and weight loss
stomach upset and nausea
confusion and irritability
If deficiency continues, symptoms can get worse, and
some damage can be permanent. This can include damage to the heart, and
changes to the nervous system.
There is little chance of getting too much thiamine, even when it is
taken at high doses. Because it is water soluble and not stored in the
body, it is not likely to build up to toxic levels. In older people with
low levels of thiamine, taking vitamin B1 pills has improved their
lives by decreasing both blood pressure and weight.
In isolated cases, however, thiamine toxicity has occurred
from injections or concentrated formulas used with hospital patients.
Toxicity symptoms include nervous
and a rapid pulse.