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Facts about Thiamin

R. Elaine Turner and Wendy J. Dahl

Why do we need thiamin?

Thiamin is one of the B vitamins otherwise known as vitamin B1.

Figure 1. Thiamin is also called vitamin B1.
Figure 1.  Thiamin is also called vitamin B1.
Credit: Detail of image by Tanakawho. CC BY-NC 2.0.

We need thiamin to use the carbohydrates we eat. Thiamin helps turn carbohydrates into energy for the body. The body also needs thiamin to use some of the amino acids that make up proteins.

What happens if we do not get enough thiamin?

A lack of thiamin causes the disease beriberi. People with beriberi have difficulty standing, walking, and controlling their muscles. This disease was common in the 1800s in Southeast Asian countries when people started eating white "polished" rice instead of brown rice. Removing the outer husks of rice removes most of the thiamin.

It is very easy to get enough thiamin in the diet because it is added to many processed grains. However, people affected by alcohol use disorder or who consume a very low-quality diet may suffer from a thiamin deficiency.

How much thiamin do we need?

Table 1 lists recommended daily allowances for thiamin.

Table 1. 

Recommended daily intakes of thiamin by life stage.

Life Stage

Thiamin (mg/day)

Men, ages 19+


Women, ages 19+






mg = milligrams


How can we get enough thiamin?

The best sources of thiamin are enriched, fortified, or whole-grain breads and cereals. Thiamin is one of four vitamins added to enriched grain products. Look for the word "thiamin" in the ingredient list on the label to see if it has been added:

INGREDIENTS: Water, enriched flour (wheat flour, niacin, iron, thiamin, riboflavin, folic acid, enzyme), whole wheat flour, honey...

Other good sources of thiamin are pork, legumes (beans and lentils), orange juice, and sunflower seeds. Table 2 lists some foods and the amount of thiamin they contain.

Table 2. 

Food examples and milligrams per serving of thiamin in each.


Thiamin (mg per serving)

Pork chop, boneless, lean, broiled, cooked, 3 oz


Ready-to-eat cereal, 1 cup


Spaghetti, whole wheat enriched, cooked, 1 cup


Orange juice, 1 cup, raw


Squash, 1 cup chopped, raw


Rice, Enriched, white, cooked, 1 cup


Sunflower seeds, dry roasted with salt 2 oz


Black beans, cooked, boiled, with salt ½ cup


mg = milligrams

oz = ounces


How should foods be prepared to retain thiamin?

Thiamin can be lost or destroyed in foods when they are cooked, especially if they have long cooking times or are cooked in large amounts of water. However, because many thiamin sources do not need to be cooked, this is not a major concern.

What about supplements?

Most people get plenty of thiamin in their diet, so supplements are usually not needed. Thiamin is included in most multivitamin supplements.

It is very easy to get enough thiamin in the diet because it is added to many processed grains. However, people affected by alcohol use disorder or who consume a very low-quality diet may suffer from a thiamin deficiency.

Where can I get more information?

The Family and Consumer Sciences (FCS) agent at your county Extension office may have more written information and nutrition classes for you to attend. Also, a registered dietitian (RD or RDN) can provide reliable information to you.

Reliable nutrition information may be found on the Internet at the following sites:


Institute of Medicine. (1998). The National Academies Collection: Reports funded by National Institutes of Health Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington (DC): National Academies Press (US) National Academy of Sciences.

U.S. Department of Agriculture Food Products Database. United States Department of Agriculture Website. Updated April 2018. Accessed June 15, 2022.

Also Available in: Español

Publication #FCS8667

Release Date:May 11, 2022

Related Experts

Dahl, Wendy J.


University of Florida

Turner, R Elaine


University of Florida

Related Topics

Fact Sheet
General Public

About this Publication

This document is FCS8667, one of a series of the Department of Family, Youth and Community Sciences, UF/IFAS Extension. Original publication date June 2001. Revised June 2015, September 2018, and May 2022. Visit the EDIS website at for the currently supported version of this publication.

About the Authors

R. Elaine Turner, PhD, RD, dean and professor, College of Agricultural and Life Sciences; and Wendy J. Dahl, assistant professor, Food Science and Human Nutrition Department; UF/IFAS Extension, Gainesville, FL 32611.


  • Wendy Dahl