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Publication #FCS8667

Facts About Thiamin1

R. Elaine Turner and Wendy J. Dahl2

Why do we need thiamin?

Thiamin is one of the B vitamins. It is also called vitamin B1.

Figure 1. 

Thiamin is also called vitamin B1.


Detail of image by Tanakawho. CC BY-NC 2.0.

[Click thumbnail to enlarge.]

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 don’t 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’s very easy to get enough thiamin in the diet because it’s added to many processed grains. However, people who abuse alcohol or have a very poor diet may suffer from a thiamin deficiency.

How much thiamin do we need?

Table 1 lists recommended daily allowances of 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, cooked, 3 oz


Ready-to-eat cereal, 1 cup


Spaghetti, enriched, cooked, 1 cup


Orange juice, 1 cup


Wheat germ, ½ oz


Rice, Enriched, white, cooked, 1 cup


Sunflower seeds, 2 oz


Black beans, cooked, 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 don’t 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.

Research has not yet found problems from consuming too much thiamin from food or supplements. However, there is no need to take a supplement with more than 100 to 150% of the Daily Value for thiamin.

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) can provide reliable information to you.

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



This document is FCS8667, one of a series of the Department of Family, Youth and Community Sciences, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. First published: June 2001. Revised April 2012. Visit the EDIS website at


R. Elaine Turner, PhD, RD, associate dean and professor, College of Agricultural and Life Sciences, and Wendy J. Dahl, assistant professor, Food Science and Human Nutrition Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611.

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other UF/IFAS Extension publications, contact your county's UF/IFAS Extension office.

U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.