Last updated on 7-7-2025 by Thérésa Lebacq
Why do we study vitamin B1 intake?
- Vitamin B1 is a water-soluble vitamin, also known as thiamine, essential for energy metabolism. It plays a key role in neural function and cardiovascular health.
- Important sources of vitamin B1 are pork, poultry, fish, whole grains, yeast, pulses, shellfish and raw vegetables. Vitamin B1 deficiency can lead to cardiovascular and neurological conditions. Individuals with a high intake of alcohol have an increased vitamin B1 requirement.
- The Belgian Superior Health Council states that a healthy and varied diet provides more than enough vitamin B1. Considering this, supplements are not recommended for the general population and in case of suppletion, it is advised to keep the intake from supplements below 5 mg/day.
- Vitamin B1 is considered non-toxic, as even oral doses of up to 500 mg/day have shown no adverse effects. Excessive doses are excreted via the urine.
How do we study it?
- Insufficient vitamin B1 intake from food and supplements was assessed by comparing the habitual vitamin B1 intake of the population with the reference values set by the European Food Safety Authority, i.e. 0.072 mg per megajoule (MJ) consumed for all ages.
- Vitamin B1 is involved in energy-yielding reactions. According to EFSA, there is a positive relationship between vitamin B1 requirement and energy requirement. On an individual level, this means that people with a higher energy intake, have a higher vitamin B1 need. To take this effect into account, the vitamin B1 requirement and intake are expressed per megajoule, which is a unit of energy.
- The prevalence of excessive vitamin B1 intake from food and supplements was not estimated in absence of a safety reference value.
- Habitual intake of vitamin B1 was analysed using the SPADE® program. A detailed description on the methodology for deriving the habitual vitamin B1 intake, the type of the reference values used and the age-and-sex-specific values of these references can be found here.
- Due to statistical limitations, the results of vitamin B1 cannot be presented by educational level or region.
KEY RESULTS
The mean vitamin B1 intake from food only is 0.15 mg/MJ, while the mean intake from food and supplements is 0.19 mg/MJ
The mean vitamin B1 intake from food increased from 0.13 mg/MJ in 2014-2015 to 0.15 mg/MJ in 2022-2023
Meat, meat products and substitutes (26%), and cereals and cereal products (22%) are the main contributors to vitamin B1 intake
Vitamin B1-containing supplements contribute 4% to the total vitamin B1 intake
Proportion of the population consuming a vitamin B1-containing supplement
16% of the population in Belgium aged 3 years and older uses a vitamin B1-containing supplement.
By sex
Mean vitamin B1 intake (mg/MJ) in the population aged 3 years and older, by sex, Belgium: 2022-2023
- Crude = results weighted for season, age, sex, and socioeconomic status.
- The mean vitamin B1 intake from food only is 0.15 mg/MJ in the population aged 3 years and older. The mean intake from food and supplements raises to 0.19 mg/MJ.
- The mean vitamin B1 intake from food does not differ between men and women. When including supplements, women (0.22 mg/MJ) have a higher mean intake than men (0.17 mg/MJ).
Proportion of the population aged 3 years and older with inadequate vitamin B1 intake, by sex, Belgium: 2022-2023
- Crude = results weighted for season, age, sex, and socioeconomic status.
- Results are based on dietary reference values defined as average requirements (AR).
- 0.4% of the population have an inadequate intake of vitamin B1 from food. This proportion is 0.3% when the intake from food and supplements is considered. Both proportions are similar in men and women.
By age
Mean vitamin B1 intake (mg/MJ) in the population aged 3 years and older, by age, Belgium: 2022-2023
- Crude = results weighted for season, age, sex, and socioeconomic status.
- Older adults (65 years and above) do not include those residing in care facilities, hospitalised individuals, or those who would have required significant assistance during interviews (e.g., people with cognitive impairments).
- The mean vitamin B1 intake from food only is lowest in adolescents (0.14 mg/MJ), similar in children and adults aged 18-64 years (0.15 mg/MJ) and highest in adults aged 65 and older (0.17 mg/MJ).
- When considering intake from food and supplements, adolescents have the lowest vitamin B1 intake (0.15 mg/MJ), compared to adult age groups (0.20 mg/MJ).
Proportion of the population aged 3 years and older with inadequate vitamin B1 intake, by age, Belgium: 2022-2023
- Crude = results weighted for season, age, sex, and socioeconomic status.
- Results are based on dietary reference values defined as average requirements (AR).
- Older adults (65 years and above) do not include those residing in care facilities, hospitalised individuals, or those who would have required significant assistance during interviews (e.g., people with cognitive impairments).
- The proportion of people with inadequate vitamin B1 intake from food is 0.8% in adolescents and 0.4% in children and adults aged 18-64 years. Adults aged 65 and older have a risk of inadequate intake which is close to null.
- The pattern remains when food and supplements are taken into account.
By year
Mean vitamin B1 intake (mg/MJ) in the population aged 3 to 64 years, by year, Belgium: 2022-2023
- Crude = results weighted for season, age, sex, and socioeconomic status.
- Adults aged 65 years and older are not included as they were not part of the target population of the 2014-2015 survey.
- The mean vitamin B1 intake from food in the population aged 3-64 years increased from 0.13 mg/MJ in 2014-2015 to 0.15 mg/MJ in 2022-2023.
- The mean vitamin B1 intake from food and supplements remained unchanged between both survey years.
Proportion of the population aged 3 to 64 years with inadequate vitamin B1 intake, by year, Belgium: 2022-2023
- Crude = results weighted for season, age, sex, and socioeconomic status.
- Results are based on dietary reference values defined as average requirements (AR).
- Adults aged 65 years and older are not included as they were not part of the target population of the 2014-2015 survey.
- The proportion of the population aged 3-64 years with an inadequate intake of vitamin B1 decreased from 2.7% in 2014-2015 to 0.4% in 2022-2023.
- A similar decrease is observed when food and supplements are taken into account.
Contribution of food and supplements
Contribution of foods and supplements to vitamin B1 intake, in the population aged 3 years and older, Belgium: 2022-2023
- Crude = results weighted for season, age, sex, and socioeconomic status.
- Meat, meat products and substitutes (26%) and cereals and cereal products (22%) are the main contributors to vitamin B1 intake.
- Additionally, vegetables contribute 8% to the vitamin B1 intake.
- On average, 4% of the total vitamin B1 intake is provided by supplements.
Please cite this page as: Sciensano. Micronutrients : Vitamin B1, Food Consumption Survey 2022-2023, June 2025, Brussels, Belgium, https://www.sciensano.be/en/results-national-food-consumption-survey-2022-2023/micronutrients-vitamins/vitamin-b1-thiamine