Vitamin B1, commonly known as thiamin, was the first of six B vitamins to be discovered. Like all other B vitamins, thiamin is a water-soluble vitamin that is not stored in the body in large amounts.

What Is The Role Of Vitamin B1 In The Body?

Some people call thiamin a “workhorse” vitamin. Thiamin is essential for the breakdown of carbohydrates and conversion of glucose into energy. The energy produced is important for the growth, development and function of the many cells throughout our bodies.

Thiamin also assists with the relay of nerve signals throughout the body, and helps to prevent complications in many organs and tissues, including the intestines, heart and brain.

How Much Vitamin B1 Do I Need?

Health Canada recommends healthy males over the age of 14 consume 1.2 mg of thiamin daily. Additionally, they recommend healthy females between the ages of 14 and 18 consume 1.0 mg of thiamin per day, and females over the age of 18 consume 1.1 mg per day. You can find a list of Health Canada’s recommendations for vitamin B1 intakes for other populations by visiting their Dietary Reference Intakes page.

Am I Getting Enough Vitamin B1?

Vitamin B1 deficiency is rare in Canada and the US as the vitamin is found in a variety of foods.

Populations at risk for thiamin deficiency include,

    • Older adults 
    • People with alcohol dependence
    • Individuals who have undergone bariatric surgery
    • Individuals with diabetes
    • People with HIV or AIDS

Some signs of thiamin deficiency include,

    • Fatigue 
    • Weight loss
    • Tingling sensations in arms and legs
    • Muscle weakness or slower reflexes
    • Nausea and vomiting
    • Weakened immunity

Severe thiamin deficiency can lead to the development of beriberi or Wernicke-Korsakoff syndrome. Wernicke-Korsakoff syndrome primarily affects individuals with alcoholism and is more common than beriberi in developed countries.

Additionally, due to thiamin’s role in the conversion of glucose into energy, prolonged thiamin deficiency can lead to the development of congestive heart failure and cognitive decline. For more information on the role of thiamin deficiency in the development of these conditions, check out Harvard’s School of Public Health.

Can I Have Too Much Vitamin B1?

Because thiamin is a a water-soluble vitamin, it is filtered out of the blood by our kidneys. This prevents the build up of thiamin in our bodies and toxicity.


Where Can I Find Vitamin B1?

As I mentioned earlier, vitamin B1 can be found in a variety of foods. Some foods naturally contain thiamin, while other foods are enriched with thiamin to increase our nutrient intake and ensure we meet the recommendations outlined by Health Canada. Some of the most thiamin-rich foods include,

    • Long-grain white rice
    • Egg noodles
    • Trout
    • Tuna
    • English muffins
    • Acorn squash
    • Mussels
    • Pork chops
    • Whole wheat bread
    • Orange juice (from concentrate)

Glasses of orange juice.

Dietary Supplements

Thiamin can also be found in supplements including, multivitamins, part of a B-vitamin complex and as individual supplements.

Interaction with Medications

Vitamin B1 interacts with some medications including, some blood pressure medications and chemotherapy drugs. It is important to check with your doctor or health care team before starting vitamin or mineral supplements, to prevent adverse effects.

For more on the role of vitamins and minerals in promoting health and supporting our bodies, check out the Micronutrient Monday series.