“Vitamin B1 (unspecified)?”Here!thiamin
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As a supplement
Talk to your doctor or pharmacist.
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A B vitamin required for carbohydrate metabolism and nerve function.
Why it’s used
Taken to meet daily thiamin needs and to correct or prevent deficiency, which can occur with poor diet or certain health conditions.
What the evidence is for
preventing and correcting thiamin deficiency.
What the evidence says
NIH's Office of Dietary Supplements describes thiamin's established role in energy metabolism and its well-documented use in preventing and treating deficiency, including beriberi and Wernicke-Korsakoff syndrome in clinical settings. Outside of deficiency correction, evidence for benefits of supplementation in people who are not deficient is limited.
Dose studied
1.1–1.2 mg — adult RDA, per NIH ODS.
Context
The adult RDA is 1.1-1.2 mg per day, per NIH ODS. No tolerable upper intake level has been established, as thiamin has not been shown to cause harm at typical intakes.
Rumors
Correcting thiamin deficiency and preventing beriberi — nerve damage and wasting, and in severe cases heart failure or the memory loss and disorientation of Wernicke-Korsakoff syndrome.
Supports — establishedhealth and safety evidence
Studied in: people with diagnosed thiamin deficiency (e.g., beriberi, alcohol-related deficiency).
Measured as an outcome.
- Thiamin - Health Professional Fact Sheet (Regulatory) · Funding not checked
How much is a reference amount
- 1.1 mg a dayfor adults 19 and over, women · Recommended Dietary Allowance
No upper limit has been set — the data was not sufficient to set one, which is a gap in the research rather than a finding about safety.
- 1.2 mg a dayfor adults 19 and over, men · Recommended Dietary Allowance
No upper limit has been set — the data was not sufficient to set one, which is a gap in the research rather than a finding about safety.
No UL: the FNB found no reports of adverse effects from high thiamin intakes and did not set one. That is a gap in the adverse-effect data, not a finding of safety.
Every applicable line is shown because we don’t know which one is yours, and a reference intake is a target for a population, not a threshold for harm.