nutrient

Vitamin B1 (thiamin)

A water-soluble vitamin that helps cells use carbohydrate and amino acids for energy metabolism.

Thiamin is present as free thiamin and phosphorylated compounds in foods. Digestion removes phosphate groups before most absorption.

What it does

Thiamin diphosphate is a cofactor for enzymes that connect carbohydrate breakdown with energy production and for branched-chain amino-acid metabolism. Tissues with high energy demand are particularly dependent on these reactions.

Where it comes from

Whole grains, pork, legumes, nuts and fortified foods can contribute. Food preparation and processing affect the forms recorded in a composition database.

Food sources

Per 100 g

Food amounts per 100 g
Food	Per 100 g
Ground flaxseed	0.54 mg
Chia seeds, dry	0.5 mg
Rolled oats	0.41 mg
Atlantic salmon, farmed, cooked (SR Legacy 2018)	0.34 mg
Brown rice, long-grain, raw	0.33 mg

Show 29 more foods

Food amounts per 100 g
Food	Per 100 g
English walnuts, raw	0.23 mg
Atlantic salmon, farmed, raw (SR Legacy 2018)	0.21 mg
Lentils, cooked and salted (SR Legacy 2018)	0.17 mg
Almonds	0.16 mg
Hummus, commercial	0.15 mg
Rainbow trout, wild, raw (SR Legacy 2018)	0.12 mg
Braised chicken breast	0.1 mg
Braised chicken drumstick	0.09 mg
Atlantic sardines, canned in oil (SR Legacy 2018)	0.08 mg
Almonds, dry-roasted and salted	0.08 mg
Spinach, raw (SR Legacy 2018)	0.08 mg
Spinach	0.08 mg
Grape tomatoes, raw	0.08 mg
Russet potato, raw	0.07 mg
Navel orange, raw	0.07 mg
Mature carrots, raw	0.07 mg
White rice, long-grain, raw	0.07 mg
Soy milk, unsweetened and shelf-stable	0.06 mg
Low-fat milk, 1% and fortified	0.06 mg
Banana, ripe, raw	0.06 mg
Orange bell pepper, raw	0.06 mg
Plain whole-milk yogurt	0.06 mg
Orange sweet potato, peeled and raw	0.05 mg
Oat milk, unsweetened and refrigerated	0.04 mg
Carrots, frozen and unprepared	0.04 mg
Light tuna, canned in water, drained	0.03 mg
Greek yogurt, plain nonfat	0.02 mg
Cottage cheese, 2% fat	0.02 mg
Red Delicious apple, raw	<0.01 mg

USDA food values are mass per 100 g, so an energy-based PRI cannot be divided into them without an energy intake denominator.

About these amounts

These values describe the named food and preparation. A 100 g comparison is not a suggested serving. Small amounts are rounded for display; an unreported amount is not zero.

Healthy European adults. Population reference intake: 0.1 mg/MJ. These are population references, not individual targets.

Portions recorded by the source

Hummus, commercial: 2 tablespoon (33.9 g) — 0.05 mg.
Braised chicken breast: 1 piece (174 g) — 0.17 mg.
Braised chicken drumstick: 1 drumstick (104 g) — 0.09 mg.
Almonds, dry-roasted and salted: 1 cup (135 g) — 0.11 mg.
Low-fat milk, 1% and fortified: 1 cup (246 g) — 0.14 mg.
Light tuna, canned in water, drained: 1 can (142 g) — 0.04 mg.
Greek yogurt, plain nonfat: 1 container (156 g) — 0.03 mg.
Cottage cheese, 2% fat: 1 cup (220 g) — 0.04 mg.

The source records and EFSA guidance are linked in References below.

Worth knowing

Small stores need regular replenishment. The body stores only small amounts of thiamin, mainly in the liver. Regular dietary supply matters; alcohol dependence can also impair absorption and storage.
Processing changes thiamin records. Milling and some cooking methods can lower thiamin, while enrichment and fortification add it back to selected foods. Preparation and product history belong with the nutrient amount.

A closer look

Digestion releases thiamin

Much of the thiamin in food is attached to phosphate groups. Digestion removes those groups before absorption; cells then make the working coenzyme forms they need.

How thiamin helps use fuel

Cells use thiamin to make thiamin diphosphate, a helper molecule for enzymes involved in carbohydrate and amino-acid metabolism. This helps explain why thiamin is needed to release energy from food; it does not mean extra thiamin supplies extra energy.

References

Source-checked local draft.
Human editorial review pending.