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Thiamin (B1)

Vitamin Unit: mg

B vitamin (B1) essential for energy metabolism and nerve function. Deficiency causes beriberi.

Recommended Daily Allowance (RDA)

1.2
Adult Male
mg/day
1.1
Adult Female
mg/day
Daily Requirements by Life Stage 16 groups
Life StageRDA / AI (mg/day)Upper Limit (mg/day)
Children 1-3 years0.50
Children 4-8 years0.60
Males 9-13 years0.90
Females 9-13 years0.90
Males 14-18 years1.2
Females 14-18 years1.0
Males 19-30 years1.2
Females 19-30 years1.1
Males 31-50 years
Females 31-50 years
Males 51-70 years
Females 51-70 years
Males 70+ years
Females 70+ years
Pregnancy1.4
Lactation1.4

Top Foods Highest in Thiamin (B1)

Amount per 100g serving. Values in mg per 100g.

Foods Highest in Thiamin (B1) (Table)

#FoodPer 100gGroup
1Yeast extract spread23.4 mgVegetables and Vegetable Products
2Leavening agents, yeast, baker's, active dry11.0 mgBaked Products
3Formulated bar, POWER BAR, chocolate8.1 mgSnacks
4Soup, cream of vegetable, dry, powder5.2 mgSoups, Sauces, and Gravies
5Cereals ready-to-eat, RALSTON Enriched Wheat Bran flakes4.7 mgBreakfast Cereals
6Cereals ready-to-eat, RALSTON Corn Flakes4.5 mgBreakfast Cereals
7Bacon, meatless4.4 mgLegumes and Legume Products
8Luncheon slices, meatless4.0 mgLegumes and Legume Products
9Babyfood, cereal, rice, with bananas, dry4.0 mgBaby Foods
10Babyfood, cereal, high protein, with apple and orange, dry3.8 mgBaby Foods
11Babyfood, cereal, mixed, with bananas, dry3.8 mgBaby Foods
12Formulated bar, MARS SNACKFOOD US, SNICKERS MARATHON Honey N3.4 mgSnacks
13Seeds, sunflower seed flour, partially defatted3.2 mgNut and Seed Products
14Formulated bar, MARS SNACKFOOD US, SNICKERS MARATHON Energy 2.9 mgSnacks
15Babyfood, cereal, oatmeal, with honey, dry2.8 mgBaby Foods
16Rice bran, crude2.8 mgCereal Grains and Pasta
17Formulated bar, MARS SNACKFOOD US, SNICKERS MARATHON MULTIGR2.7 mgSnacks
18Formulated bar, MARS SNACKFOOD US, SNICKERS MARATHON Chewy C2.7 mgSnacks
19Seeds, sesame flour, high-fat2.7 mgNut and Seed Products
20Veggie burgers or soyburgers, unprepared2.7 mgLegumes and Legume Products

Health Effects of Thiamin (B1)

Function

Thiamin (B1) is essential for energy metabolism as a coenzyme (TPP) in carbohydrate metabolism, particularly the pyruvate dehydrogenase complex and the pentose phosphate pathway.

Deficiency Signs

Thiamin deficiency causes beriberi (wet: cardiac failure; dry: peripheral neuropathy) and Wernicke-Korsakoff syndrome (especially in alcoholics). Requirements increase with carbohydrate intake.

Excess / Toxicity

No adverse effects from high oral intake; excess is rapidly excreted by kidneys. No UL established.

Absorption & Interactions

How It’s Absorbed

Absorbed in the jejunum via active transport (THTR1/2 transporters) at low concentrations and passive diffusion at high concentrations. Phosphorylated forms in food are hydrolyzed by phosphatases first.

Key Interactions
Magnesium Enhancer
Magnesium is required as a cofactor for thiamin-dependent enzymes; magnesium deficiency impairs thiamin utilization

Estimated Thiamin (B1) Adequacy by Country

Estimated from national food supply composition (FAO food balance sheets). Shows food supply availability relative to Estimated Average Requirement (EAR), not actual intake. Does not account for fortification, supplements, or distribution inequality.

180 countries0 below 50% EAR180 above 100% EARAvg: 181% EAR
% of EAR from food supply:0-25%25-50%50-75%75-100%100-150%>150%

Frequently Asked Questions

How much Thiamin (B1) do I need per day?

Adult males need 1.2 mg/day and adult females need 1.1 mg/day.

Which food has the most Thiamin (B1)?

The food highest in Thiamin (B1) is Yeast extract spread with 23.4 mg per 100g.

What does Thiamin (B1) do in the body?

B vitamin (B1) essential for energy metabolism and nerve function. Deficiency causes beriberi.