What Foods Are High in B1? Thiamine-Rich Sources

October 31, 2025 •

4 min read

According to the National Institutes of Health, thiamine (vitamin B1) is essential for converting food into energy and supporting a healthy nervous system. Finding out what foods are high in B1 is a practical step toward ensuring your diet meets this vital nutrient's requirements for overall health and well-being.

Quick Summary

This guide details the best natural and fortified food sources of thiamine, including animal products like pork and fish, plant-based options such as whole grains and legumes, and enriched cereals. It covers the importance of incorporating these foods into your diet to avoid deficiency.

Key Points

Diverse Sources: Both animal products like pork and salmon, as well as plant-based options such as sunflower seeds, whole grains, and legumes, are excellent sources of vitamin B1.
Fortified Foods are Key: Many breakfast cereals, breads, and grains are fortified with thiamine, offering an accessible and reliable way to meet daily intake requirements.
Consider Cooking Methods: Because thiamine is water-soluble and heat-sensitive, steaming or quick cooking is preferable to prolonged boiling to preserve the vitamin content.
Prevent Deficiency: Including a variety of thiamine-rich foods is crucial for preventing deficiency, which can cause severe neurological and cardiovascular problems.
Meet Daily Needs: Most adults need 1.1-1.2 mg of thiamine daily, a target that can be met through a balanced diet including pork, whole grains, nuts, and fortified products.

The Importance of Thiamine (Vitamin B1)

Thiamine, or vitamin B1, is a crucial water-soluble vitamin that plays an indispensable role in the body's metabolic processes. It acts as a coenzyme, helping to convert carbohydrates into usable energy, and is vital for the proper function of the nervous system, muscles, and heart. Unlike fat-soluble vitamins, the body does not store large amounts of thiamine, so a continuous dietary intake is necessary. A deficiency in this essential nutrient can lead to a condition called beriberi, which affects the heart and nerves, or Wernicke-Korsakoff syndrome, a severe neurological disorder. Therefore, making informed choices about what foods are high in B1 is fundamental for maintaining good health.

Top Animal-Based Sources of Thiamine

Many animal products are excellent providers of vitamin B1. Incorporating a variety of these into your diet can help you meet your daily needs. The cooking method is important, as thiamine is sensitive to heat, so steaming or baking may be preferable to high-heat methods.

Pork: Lean pork is one of the richest natural sources of thiamine. A single serving can provide a significant portion of the recommended daily intake. Pork loin and tenderloin are particularly good options.
Fish and Seafood: Several types of fish and shellfish contain notable amounts of thiamine. Salmon, tuna, trout, and mussels are all excellent choices.
Eggs: A staple in many diets, eggs offer a modest but consistent amount of vitamin B1.

Plant-Based and Fortified Sources of Thiamine

For those following a vegetarian or vegan diet, or simply looking to diversify their nutrient intake, a wide array of plant-based foods and fortified products are available. These sources can be just as effective in providing adequate thiamine.

Legumes: Beans, lentils, and green peas are fantastic sources of thiamine. Black beans, navy beans, and lentils, in particular, pack a high nutritional punch.
Nuts and Seeds: Sunflower seeds are a powerhouse of thiamine, as are nuts like pecans and macadamia nuts.
Whole Grains: Unlike their refined counterparts, whole grains like brown rice, oatmeal, quinoa, and whole wheat bread retain their thiamine content.
Nutritional Yeast: Often used as a cheese substitute, nutritional yeast is a very rich source of thiamine and is easily sprinkled onto many dishes.
Fortified Cereals: Many breakfast cereals and breads are fortified with B vitamins, including thiamine, to help prevent deficiency. These can be an easy way to boost your daily intake.
Certain Vegetables: Some vegetables, such as acorn squash, asparagus, and potatoes, contain good levels of thiamine.

Comparing Thiamine Content: Animal vs. Plant Sources

To help illustrate the difference in thiamine content, here is a comparison of some popular animal and plant-based food sources. (Values are approximate and can vary based on preparation and portion size.)


Food Source	Type	Thiamine Content (per standard serving)	Notes
Pork Loin	Animal	0.5-0.6 mg	Excellent source, high in B-vitamins
Pecans	Plant	0.6 mg	Very high for a plant source
Salmon	Animal	0.2-0.3 mg	Good source, also rich in Omega-3s
Black Beans (cooked)	Plant	0.1-0.2 mg	Good vegetarian source
Fortified Cereal	Fortified	~1.2 mg	Can meet daily needs in one serving
Brown Rice (cooked)	Plant	~0.18 mg	Much higher than unenriched white rice
Nutritional Yeast	Fortified	Very High	Excellent vegan source, often added to foods

Factors Affecting Thiamine Content

It's important to remember that several factors can impact the thiamine content of food. Thiamine is water-soluble, meaning it can leach out into cooking water, especially with long cooking times. High heat can also destroy the vitamin. This is why cooking methods like steaming or quick stir-frying are often recommended over boiling. Additionally, food processing, like the refining of white rice or white flour, removes most of the naturally occurring thiamine, which is why enrichment is so crucial. Chronic alcohol consumption can also interfere with the absorption of thiamine.

Conclusion: A Well-Rounded Approach to Thiamine

Ensuring you get enough thiamine does not require a complicated diet. By incorporating a mix of whole grains, legumes, lean meats like pork, and fortified products, you can easily meet your daily recommended intake. Diversifying your food choices from both animal and plant sources is the best strategy. For instance, enjoying a meal with pork tenderloin and steamed asparagus one day, and a bowl of lentil soup with whole wheat bread the next, provides a balanced approach to obtaining this essential nutrient. Pay attention to preparation methods to preserve as much of the vitamin as possible. By being mindful of these dietary habits, you can support your body's energy production and overall health. For further reading, an authoritative resource on the vitamin is the National Institutes of Health's fact sheet: ods.od.nih.gov/factsheets/Thiamin-HealthProfessional.

Frequently Asked Questions

Thiamine is another name for vitamin B1, a water-soluble vitamin that helps the body convert food into energy. It is essential for nerve function, muscle contraction, and a healthy heart.

A severe thiamine deficiency can lead to a condition called beriberi, which affects the nerves and heart. Symptoms can include fatigue, irritability, memory loss, and in severe cases, heart problems and neurological issues.

Yes, many plant-based foods are excellent sources of thiamine. These include nutritional yeast, legumes (beans and lentils), sunflower seeds, whole grains, and some vegetables like peas and asparagus.

Fortified foods, such as certain breakfast cereals, breads, and enriched rice, have thiamine added back to them after processing. They can provide a significant portion of the daily recommended intake and are especially important where natural intake may be low.

Yes, thiamine is sensitive to heat and can be destroyed during cooking, especially with prolonged, high-heat methods. As a water-soluble vitamin, it can also leach into cooking water that is later discarded.

The Recommended Dietary Allowance (RDA) for thiamine is 1.2 mg per day for adult men and 1.1 mg per day for adult women. This amount increases during pregnancy and lactation.

There is no Tolerable Upper Intake Level (UL) established for thiamine from food and supplements because there have been no reported adverse effects from high intakes. Excess thiamine is typically excreted by the body.