Glossary: Vitamin B1

Close Window Close Button

vitamin B1

Also known as: Thiamin; Thiamine

What is it?

The chief function of this VITAMIN is to cooperate with other members of the B-COMPLEX in converting GLUCOSE to energy, which fuels the body. It is also important for a healthy nervous system. For years doctors blamed beriberi, a devastating nerve disease that once rampaged through Asia, on something harmful in food. Only with the turn of the twentieth century did scientists discover that rice bran, removed to create the polished white rice Asians preferred, contained something that prevented beriberi. And only in 1926 were crystals of this "beriberi vitamine" used to cure beriberi in people. Today we know this substance as thiamin or vitamin B1 and it is one of the nutrients added to grains and flours during the enrichment process.


U.S. RDA FOR VITAMIN B1

babies: birth to 6 months 6 months to 1 year	0.3 mg per day 0.4 mg per day
children: 1 to 3 years 4 to 6 years 7 to 10 years	0.7 mg per day 0.9 mg per day 1 mg per day
men and boys: 11 to 14 years 15 to 50 years 51+ years	1.3 mg per day 1.5 mg per day 1.2 mg per day
women and girls: 11 to 50 years 51+ years	1.1 mg per day 1 mg per day
pregnant women	1.5 mg per day
nursing mothers: first 6 months second 6 months	1.6 mg per day 1.6 mg per day
nursing mothers: first 6 months second 6 months	1,300 RE per day 1,200 RE per day

Deficiency Symptoms

Depression, irritability, attention deficit, muscular weakness. Severe thiamin deficiency can cause beriberi with symptoms including edema, paralysis and heart failure. Those most apt to be lacking in thiamin are alcoholics and those who constantly junk out on soft drinks, candy, pretzels, chips and other high-carb foods made with unenriched flours.

Good Sources

Brewer's yeast, meats (especially pork and liver), peas and beans, both fresh and dried, whole or enriched grains and breads.

Precautions

Being water soluble, thiamin tends to leach out in the cooking water. It is also destroyed by heat. Indeed, as much as 30 percent of the thiamin can be lost as a loaf of bread bakes and another 10 to 30 percent as a slice of it toasts. Alcohol impairs the body's ability to absorb thiamin, as does tea, if drunk in prodigious quantities.