Every tissue in our body needs vitamin B1 to function correctly. Vitamin B1 was the first B vitamin discovered, hence its name. The importance of this organic nutrient on our bodies is so great that lacking in it or consuming it in excess can result in life-threatening health risks.
This article provides detailed information about the best vitamin B1 foods, the function of thiamine, recommended daily intake, deficiency, etc.
Vitamin B1 Discovery
The discovery of vitamin B1 dates back to the 19th century, and many people contributed to the discovery over time. As far back as 1897, a Dutch scientist named Christiaan Eijkman discovered the dietary cause of beriberi. Namely, he noticed that chicken fed with white rice often developed polyneuritis (leg paralysis), while those on the unpolished brown rice diet didn’t.
In 1910, a Japanese scientist, Umetaro Suzuki, was the first to discover aberic acid (vitamin B1) in rice bran. He found that this substance played a crucial role in preventing beriberi—a disease caused by vitamin B1 deficiency.
In 1926, Jansen and Donath isolated and crystallized the anti-polyneuritis factor in pigeons (thiamine). However, it wasn’t until 1936 that Williams and Cline synthesized thiamine.
Thiamine Function
Vitamin B1 performs a wide range of functions in the body, vital for the proper functioning of different organs—heart, kidneys, liver, etc.
These are some of its most critical thiamine functions:
- The primary vitamin B1 function is supporting the development and growth of organs and systems.
- It helps with fat, carb, and protein metabolism.
- It promotes intercellular processes by helping synthesize ATP-energy.
- It plays a crucial role in converting carbs to glucose for energy production.
- It helps form functional blood cells by breaking down the fats and carbohydrates in foods.
- Vitamin B1 helps maintain a healthy digestive system.
- It promotes heart health.
- It prevents cell destruction by participating in the formation of nerve endings of the myelin sheath.
- Another critical thiamine function is the immune system strengthening.
- It promotes nutrient absorption by keeping the digestive system’s muscle tone smooth.
- It enhances cognitive ability.
- It promotes eye health (there’s a correlation between vitamin B1 and eyesight).
- It supports the process of transporting oxygen to body tissues.
Some of the Best Thiamine Foods
Unlike particular vitamins that can be sourced from only one or a handful of natural foods, vitamin B1 is present in more than 100 plant and animal sources. The high availability of vitamin B1 in foods makes it less challenging to maintain a good diet and avoid deficiency.
Thiamine is also present in vitamin or multivitamin supplements form. However, it’s essential to note that different food sources and multivitamins contain different vitamin B1 levels.
The following paragraphs discuss some of the most common vitamin B1 foods.
Salmon
Salmon’s thiamine content ranges from 0.016 to 0.494 mg per 100 g. The farmed Atlantic salmon cooked with dry heat offers 0.241 mg of thiamine per 100 g, providing various thiamine benefits.
Tuna
Thiamine content in tuna ranges from 0.008 to 0.278 mg per 100 g. Raw bluefin tuna offers 0.241 mg of vitamin B1 per 100 g. Bluefin tuna cooked with dry heat offers the highest thiamine dose—0.278 mg per 100 g.
Trout
Trout contains 0.06–0.426 mg of thiamine per 100 g. The raw wild rainbow trout offers 0.123 mg of vitamin B1 vitamin per 100 g. On the other hand, trout cooked using dry heat provides the highest amount of the B1 vitamin (0.426 mg per 100 g), allowing you to reap full vitamin B1 benefits.
Catfish
Catfish are mild, firm, low-fat freshwater fish and one of the essential foods with vitamin B1. Its skin is inedible and should be removed before preparation. A 3 oz portion of wild freshwater dry-cooked catfish offers 16% DRI of thiamine. This freshwater fish is also rich in vitamin B12 and contains smaller amounts of vitamin B6, vitamin A, folate, and riboflavin.
Flaxseeds
Flaxseeds contain 0–2.9 mg of thiamine per 100 g, making them some of the top vitamin-B1-rich foods. Unprocessed flaxseeds contain 1.644 mg of thiamine in 100 g.
Flaxseed products such as General Mills Total Plus Omega-3s Honey Almond Flax and Kashi GoLean Crunch! Honey Almond can also be a good source of this vitamin. The former offers the highest amount of vitamin B1 per 100 g (2.9 mg), while the latter provides only 0.161 mg per 100 g.
Sunflower Seeds
Sunflower seeds also belong to the category of foods rich in vitamin B1. Namely, they contain 0.106–1.48 mg of vitamin B1 per 100 g. While dried seeds offer the highest thiamine levels, salted oil roasted seeds offer a meager 0.32 mg of thiamine per 100 g serving.
Macadamia Nuts
Macadamia nuts are also great food sources of thiamin, containing 0.71–1.195 mg of thiamine per 100 g. Raw macadamia nuts offer the highest level of thiamine (1.195 mg per 100g). In comparison, dry roasted macadamia nuts with salt offer the lowest amount of vitamin B1 (0.71 mg per 100 g).
Navy Beans
Navy beans are also among foods containing thiamine, offering 0.141–0.775 mg of thiamine per 100 g. Raw mature beans contain the highest amount, while unsalted boiled beans contain only 0.237 mg of the B1 vitamin per 100 g.
Black Beans
Black beans offer 0.244–0.9 mg of thiamine per 100 g. Mature raw black beans provide the highest amount possible, while boiled black beans without salt contain the least amount.
Asparagus
Asparagus is also one of the significant vitamin B1 food sources, offering 0.022–0.162 mg of thiamine per 100 g. The amount of thiamine greatly depends on the preparation method. For example, a canned asparagus cream soup prepared with water contains the least thiamine. Boiled asparagus, on the other hand, offers the highest amount of vitamin B1 per 100 g.
Soy Milk
The thiamine content of soy milk ranges from 0.02 to 0.154 mg per 100 g. Namely, all flavors of unsweetened Soymilk with added calcium and vitamins A and D contain the highest levels of the B1 vitamin per 100 g serving. In contrast, the Vitasoy Light Vanilla Soymilk by Vitasoy USA offers the least amount of thiamine.
Green Peas
You can quickly meet your thiamine recommended daily intake with green peas. A 100 g of unprepared frozen green peas feature 0.26 mg of thiamine, making it an excellent vitamin B1 food option.
Tofu
Tofu offers 0.03–0.494 mg of thiamine per 100 g. Tofu yogurt contains about 0.06 mg of thiamine per 100 g, while dried-frozen tofu (koyadofu) provides the highest amount of thiamine (0.494 mg per 100 g).
Brown Rice
Brown rice also found its place among the best foods that contain vitamin B1, offering 0.096–0.413 mg of thiamine per 100 g. While the raw, medium-grain brown rice provides the highest thiamine level, the raw long-grain variant provides 0.401 mg of vitamin B1 per 100 g.
Sources of Vitamin B1 in Supplement Form
Although thiamine foods are the best and healthiest sources of this vitamin, many find it challenging to maintain the recommended daily intake of vitamin B1 through diet.
If you suffer from a vitamin B1 deficiency and are looking to rapidly replenish your thiamine levels, getting a B1 supplement or multivitamins that provide at least 100% DV of vitamin B1 is a great option.
Unfortunately, excessive consumption of thiamine supplements may lead to severe complications. Here’s a list of the most common vitamin B1 side effects you might encounter upon excessive thiamine consumption:
- Stomach upset
- Eye and skin irritation
- Rapid heartbeat
- Respiratory tract infection
- Rash
- Nausea and vomiting
Recommended Daily Intake of Thiamine
Thiamine intake depends on many factors like age, gender, and activity level. The table below highlights recommended intake for different members of the general population.
| Population | RDI (mg) |
| Athletes and adults that engage in strenuous work | 2.5–3.0 |
| Adult males | 1.2–2.5 |
| Pregnant and breast-feeding females | 1.5 |
| Adult females | 1.1 |
| Children | 0.2–0.9 |
Thiamine Deficiency
Even though there are many vitamin-B1-rich foods available, thiamine deficiency is still a relatively common occurrence. Like every other kind of nutrient deficiency, the lack of this essential nutrient can result in serious, even fatal, health situations.
There are at least 12 different symptoms of thiamine deficiency. Recognizing them could help with early deficiency detection, which is an essential part of the treatment.
Deficiency in this essential nutrient is particularly prevalent in low- and middle-income countries due to poor nutrition. However, inadequate diet isn’t the only factor increasing the risk of vitamin B1 deficiency. There are also alcoholism, HIV/AIDS, diabetes, etc.
Let’s have a look at the most common vitamin B1 deficiency symptoms.
Beriberi
Beriberi is a severe nervous system disease. There are two types—dry and wet. Dry beriberi leads to decreased muscle strength and muscle paralysis, while wet beriberi leads to problems with the heart and circulatory system. Severe cases of wet beriberi may lead to heart failure.
Loss of Appetite
Loss of appetite, otherwise known as anorexia, is one of the early symptoms of vitamin B1 deficiency. Because thiamine plays a role in regulating satiety, inadequate intake of vitamin B1 can disrupt the satiety center functioning, so you can feel full even when you’re not. Foods that contain thiamine can serve as a home remedy for the loss of appetite caused by deficiency, though severe cases might require supplementation.
Fatigue
There are many reasons for experiencing fatigue, and thiamine deficiency is one of them. The severity of your vitamin B1 deficiency affects the levels of fatigue. Symptoms can range from mild weakness to severe exhaustion.
Irritability
Frequent feelings of agitation and frustration may also be a sign that your vitamin B1 levels dropped below standard. Introducing foods rich in thiamine can help fight irritability caused by thiamine deficiency.
Reduced Reflexes
We already mentioned that vitamin B1 helps maintain a healthy nervous system. Therefore, deficiency in this nutrient will affect the nervous system, particularly the motor nerves, in devastating ways. For example, it can manifest as the lack of knee, ankle, and triceps reflexes.
Pins and Needles
Thiamine deficiency sufferers can feel a tingling, prickling, or burning sensation in the upper and lower limbs, especially after keeping the same pose for a long time, such as sitting or lying in an awkward position. It’s advised to consume as many thiamine-containing foods as possible to find relief for this condition.
Muscle Weakness
Muscle weakness is a commonly overlooked symptom of vitamin B1 deficiency. Although muscle weakness can be a symptom of other health issues, persistent muscle weakness might be indicative of deficiency.
Studies show that patients suffering from persistent muscle weakness caused by depleted thiamine levels find relief upon thiamine supplementation.
Blurry Vision
Although this is a common symptom of computer vision syndrome, it can also be a sign of thiamine deficiency. Inadequate thiamine intake can lead to the swelling of the optic nerve, which can cause blurry vision or even loss of vision in extreme cases.
Meeting the recommended thiamine daily intake helps protect your eyes from such issues.
Nausea and Vomiting
Gastrointestinal problems aren’t a typical sign of vitamin B1 deficiency but may sometimes occur as a symptom. This doesn’t come as a surprise, as vitamin B1 plays a crucial role in nutrient absorption. Particular gut-related complications caused by thiamine deficiency can be resolved with thiamine supplementation.
Irregular Heartbeat
Dropping thiamine levels can also affect your heart rate. Vitamin B1 deficiency may lead to a decrease in the heartbeat rate, resulting in increased fatigue, dizziness, and losing consciousness.
Panting
The effect of thiamine deficiency on the heart can manifest as shortness of breath. Namely, thiamine deficiency can cause poor blood circulation and cause the heart to be less efficient at pumping blood. As a result, fluid accumulates in the lungs and causes breathlessness, potentially leading to heart failure.
Delirium
Delirium is a mental condition manifesting as confusion, memory loss, brain fog, and even hallucinations. It can cause brain damage in severe cases. It’s often a result of alcoholism, which lowers thiamine levels in the body.
Conclusion
Vitamin B1 is an essential nutrient, and there’s an abundance of vitamin B1 foods with differing thiamine levels out there. Besides natural dietary products, supplements are an excellent source of vitamins (especially for those who find it hard to get the necessary amounts of this vitamin through diet). However, you have to be wary of the dosage, as excessive consumption may lead to serious side effects.
FAQ
Do bananas have thiamine?
Bananas do contain thiamine. However, the amount of this nutrient in bananas is relatively low compared to other vitamin B1 foods. For example, 100 g of raw banana contains only 0.031 mg of thiamine, barely meeting children’s RDI.
How much B1 do you need a day?
The required amount of vitamin B1 depends on various factors, including age, gender, and lifestyle. Children typically need far less vitamin B1 than adults (up to 0.9 mg a day), while athletes need more thiamine than other adults. Namely, athletes need as much as 2.5–3.0 mg of thiamine a day, while male adults require 1.2–2.5 mg daily.
What is vitamin B1 good for?
Vitamin B1 is vital for the proper functioning of different organs and systems. Vitamin B1 enables our bodies to produce energy to power our daily activities. It’s also crucial for preventing certain neurological, intestinal, and mental complications, as well as problems with vision.
What foods are high in thiamine?
There are more than 100 known thiamine-rich foods. Foods exceptionally high in thiamine include salmon, flaxseeds, navy beans, green peas, tofu, brown rice, and asparagus.
How to get vitamin B1?
There are two ways to obtain vitamin B1, the most popular and least expensive being through vitamin B1 foods. However, you can also buy vitamin B1 supplements online or buy multivitamins that contain enough B1 content to meet your recommended dietary intake (RDI).
