Foods high in thiamin, ranked by milligrams

The RDA is 1.2 mg a day for men and 1.1 mg for women, and pork, fortified grains, legumes, and sunflower seeds cover it easily. The mg-per-serving ranking, why refined grains are fortified for a reason, and who is actually at risk of deficiency.

1. 01

   Pork: ~0.7-0.9 mg per 3 oz, the whole-food leader

   Pork is by far the richest whole-food source of thiamin, carrying roughly 0.7 to 0.9 mg per 3 oz, most of a full day's target in one serving (USDA FoodData Central). Lean cuts are especially good, and the vitamin holds up reasonably well with normal cooking. For anyone who eats pork, thiamin is simply not a concern. For everyone else, the enriched grains, legumes, and seeds lower on this list cover the target just as reliably across a normal day.

2. 02

   Fortified and enriched grains and cereals

   Enriched white bread, white rice, pasta, and fortified breakfast cereals supply a large share of most people's thiamin, because the vitamin lost in milling is added back by law in many countries (NIH ODS). A single bowl of fortified cereal can provide a full day. This fortification is the main reason beriberi disappeared from grain-eating populations, and it is why refined grains, often criticized elsewhere, quietly do real nutritional work for the B vitamins.

3. 03

   Legumes: black beans, lentils, and green peas

   Legumes are strong plant sources of thiamin, with a cup of cooked black beans or lentils supplying a meaningful share of the daily target and green peas contributing well (USDA). They are the reason vegetarian and vegan diets rarely fall short, and they stack the thiamin with plant protein and fiber. As with the other B vitamins, legumes are one of the most efficient plant foods for covering several nutrients at once.

4. 04

   Sunflower seeds and whole grains

   Sunflower seeds carry ~0.5 mg of thiamin per ounce, among the densest seeds, and whole grains like brown rice, oats, and whole wheat retain the thiamin in their bran and germ that refining removes (USDA). These are the sources that reward eating grains in their whole form and adding seeds to meals. A handful of sunflower seeds plus a serving of whole grains meaningfully contributes to the daily target.

5. 05

   Trout, mussels, and other everyday foods

   Trout and mussels are useful animal sources of thiamin, and smaller amounts come from eggs, other fish, and vegetables like acorn squash and asparagus (USDA FoodData Central). None is a standout on its own, but together they form the background intake that, combined with pork, enriched grains, and legumes, keeps most diets comfortably above the requirement without any planning.

6. 06

   Who is actually at risk of deficiency

   For the general population, thiamin deficiency is rare thanks to widespread fortification, but specific groups remain at genuine risk. Chronic heavy alcohol use is the most important: it impairs thiamin absorption and use and can cause Wernicke-Korsakoff syndrome, a serious neurological emergency (NIH ODS). People with certain malabsorption conditions, on long-term diuretics, or after bariatric surgery are also vulnerable. For these groups thiamin is a real medical concern, which is different from the general population, for whom food easily covers it.