Sometimes spelled "thiamine," this nutrient was once called vitamin B1. Like riboflavin and niacin, thiamin is a coenzyme. It is particularly important in helping the body obtain energy from carbohydrates and certain amino acids.


Excellent sources of thiamin include pork (especially ham); liver; oysters; peas; lima beans; peanuts; bread; pasta; wheat germ; cereals; and enriched, fortified, or whole-grain foods.


A severe, long-term shortage of thiamin causes beriberi, a disease that can lead to leg paralysis and heart failure. Such shortages are rare in developed countries, however, except among extreme alcoholics.


High doses of thiamin, whether from foods or supplements, are not known to be toxic. Because evidence on this is limited, however, the Food and Nutrition Board (FNB) recommends caution.


Your Daily Allowance


Diet Power sets your Personal Daily Allowance (PDA) of thiamin at the FNB's Recommended Dietary Allowance (RDA), measured in milligrams: 1.2 for males aged 14 and up, 1.0 for females 14 to 18 years old, 1.1 for women 19 and older, and 1.4 during pregnancy and lactation. (People using hemodialysis or peritoneal dialysis, as well as those who have malabsorption syndrome, may need extra niacin.)


(In Diet Power, thiamin is sometimes specified in micrograms, which are 1000 times smaller than milligrams. When cited in micrograms, the PDA is 1200 for males aged 14 and up, 1000 for females 14 to 18 years old, 1100 for women 19 and older, and 1400 during pregnancy and lactation.)


Upper Limit


The FNB has not determined a Tolerable Upper Intake Level (UL) for thiamin.


Revising Your Allowance


If your doctor recommends a different PDA, you can change it with the Personal Daily Allowance Editor.


Color Coding of This Nutrient


The thiamin bar in your personal Nutrient History is:

In the nutrient profile of a food or recipe, the thiamin bar is:

How Complete Are Diet Power's Thiamin Readings?


For the 8500 generic items in the Food Dictionary: very complete. Only 0.7 percent list their thiamin content as "unknown."


For the 2500 chain-restaurant items: totally incomplete. All list thiamin as "unknown."


For all 11,000 items combined: not terribly complete. About 23 percent list thiamin as "unknown."


These figures mean that if you frequently log chain-restaurant foods (or user-added foods with missing thiamin readings), your Nutrient History may underreport your intake of thiamin by a few points.


To see whether a particular food has a thiamin reading, open the Food Dictionary and check the food's nutrient profile. If you find a question mark beside "Thiamin," it means the amount is unknown. (To see all foods with unknown thiamin readings, click the dictionary's PowerFoods tab and sort the foods by thiamin power; then scroll toward the bottom of the list until you see foods with question marks in the "Power Rating" column.)


Thiamin on Food Labels


Food labels are not required to report thiamin content, but many do. They may cite the content in milligrams, percent of Daily Value, or both.


The Daily Value for thiamin is 1.5 milligrams, or 1500 micrograms. This amount is not necessarily right for you, howeverit's a rough estimate meant to accommodate most of the U.S. population.


For more on label regulations, see Labels, Food.



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Last Modified: 7/27/07