What is thiamin?
Thiamin is classically known as vitamin B1 and sometimes aneurine. It was identified in the 1930s and is one of the first substances to be classified as a vitamin. Along with the other water-soluble vitamins (except vitamin C and choline), thiamin is a B-complex vitamin. The most salient role of B-complex vitamins is their involvement in energy metabolism.
What foods have thiamin and what form is found in supplements?
 |
Thiamin is found widely distributed in foods, although most contain low concentrations. Brewer’s yeast, pork, and whole grain and enriched grain products are better sources of thiamin (see Thiamin Table). Thiamin is found is nutritional supplements and for fortification as thiamin hydrochloride and thiamin nitrate (e.g. thiamin mononitrate). |
|
FOOD |
Thiamin (mg) |
FOOD |
Thiamin (mg) |
|---|---|---|---|
|
Meats |
|
Grains |
|
|
pork roast (3 oz) |
0.8 |
bran flakes (1c) |
0.6 |
|
beef (3 oz) |
0.4 |
macaroni (½ c) |
0.1 |
|
ham (3 oz) |
94 |
rice (½ c) |
0.1 |
|
liver (3 oz) |
0.2 |
bread (1 sl) |
0.1 |
|
Nuts and seeds |
|
Vegetables |
|
|
sunflower seeds (¼ c) |
0.7 |
peas (½c) |
0.3 |
|
peanuts (¼ c) |
0.1 |
lima beans (½ c) |
0.2 |
|
Almonds(¼c) |
|
corn (½ c) |
0.1 |
|
Fruits |
51 |
broccoli (½ c) |
0.1 |
|
orange juice (1 c) |
0.2 |
potato (1) |
0.1 |
|
orange (1) |
0.1 |
|
|
|
avocado (¼) |
0.1 |
|
|
How much thiamin do we need?
The RDA for men and women is 1.2 and 1 mg of thiamin. Meanwhile the RDA for pregnant and lactating women is 1.4 mg. Because thiamin is important in energy operations it is more appropriate to express thiamin recommendation based on level of additional calories burned during exercise and sport training/competition. Here recommendations 0.5 mg of thiamin would be recommended for every 1000 calories expended daily. Thus athletes expending 3000 to 6000 calories daily would have a recommendation of 1.5 and 3 mg. See DRI/RDA Table for recommendations levels for children and teens.
Does thiamin breakdown during cooking?
Similar to vitamin C, thiamin is not very stable during cooking processes. Convection cooking of meat may result in destruction of roughly half of its thiamin content. The baking of breads and the pasteurization of milk may result in destruction of approximately 25 percent and 15 percent of thiamin content, respectively. In light of its water-soluble nature, some thiamin may also be washed away in the thaw drip. The thaw drip is the watery fluid that drains from thawing meats.In addition, certain fish and shellfish contain natural thiaminases, which are enzymes that break down thiamin. Fortunately, cooking inactivates these enzymes.
Where is thiamin found in our body?
Most of the thiamin that we eat is absorbed in the small intestine. Once in the body, thiamin does not seem to have a primary organ of storage, however, the brain, kidneys, liver, and skeletal muscle seem to have higher concentrations. In fact, because of its high energy demands, the brain accounts for as much as one-half of the total thiamin in the body. Thiamin circulates around primarily aboard red blood cells (RBCs) and the activity of a thiamin associated enzyme is used to gauge thiamin status. Thiamin and its metabolites are subject to removal from the body in urine.
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