Vitamin B1 (Thiamin)
Last updated: August 9, 2026
Benefits
Helps your body turn carbohydrates from food into energy and keeps nerve and muscle signalling working normally.
How much you need
Recommended daily amounts by life stage, per NIH and NASEM Dietary Reference Intakes. Where the evidence hasn't been enough to set a full RDA (Recommended Dietary Allowance), NASEM sets an AI (Adequate Intake) instead — both are shown together below.
| Life stage | RDA / AI |
|---|---|
| Children 1–3 | 0.5 mg |
| Children 4–8 | 0.6 mg |
| Boys 9–13 | 0.9 mg |
| Girls 9–13 | 0.9 mg |
| Males 14–18 | 1.2 mg |
| Females 14–18 | 1 mg |
| Men 19–50 | 1.2 mg |
| Women 19–50 | 1.1 mg |
| Men 51–70 | 1.2 mg |
| Women 51–70 | 1.1 mg |
| Men 71+ | 1.2 mg |
| Women 71+ | 1.1 mg |
| Pregnancy 14–18 | 1.4 mg |
| Pregnancy 19–50 | 1.4 mg |
| Lactation 14–18 | 1.4 mg |
| Lactation 19–50 | 1.4 mg |
Upper limit
No tolerable upper limit has been established for Vitamin B1 (Thiamin). That doesn't mean unlimited amounts are risk-free — it means the evidence NASEM has reviewed so far hasn't been enough to set a numeric ceiling.
Best food sources
| Serving | ||
|---|---|---|
| Fortified and whole grains | — | — |
| Pork | — | — |
| Black beans and lentils | — | — |
| Sunflower seeds | — | — |
| Green peas | — | — |
Body systems & goals
Goals it supports
- Energy & stamina (emerging evidence)
Frequently asked questions
How much Vitamin B1 (Thiamin) do adult women need per day?
Adult women (19–50) need 1.1 mg of Vitamin B1 (Thiamin) per day, per NIH/NASEM Dietary Reference Intakes.
How much Vitamin B1 (Thiamin) do adult men need per day?
Adult men (19–50) need 1.2 mg of Vitamin B1 (Thiamin) per day, per NIH/NASEM Dietary Reference Intakes.
Does pregnancy change how much Vitamin B1 (Thiamin) you need?
Yes — during pregnancy (ages 19–50) the recommended amount rises to 1.4 mg per day, compared with 1.1 mg for non-pregnant adult women.
Is there an upper limit for Vitamin B1 (Thiamin)?
No tolerable upper limit has been established for Vitamin B1 (Thiamin), based on current evidence reviewed by NASEM.
What foods are highest in Vitamin B1 (Thiamin)?
Good sources include Fortified and whole grains, Pork, Black beans and lentils, Sunflower seeds, and Green peas.
How Tavita handles this
Tavita logs Vitamin B1 (Thiamin) from both the food you eat and the supplements you take, adding both into one running daily total. There's no established upper limit for Vitamin B1 (Thiamin), so Tavita tracks it against the recommended amount without implying a ceiling that doesn't exist.
Sources
Figures on this page come from the NIH Office of Dietary Supplements fact sheets and the National Academies of Sciences, Engineering, and Medicine (NASEM) Dietary Reference Intake tables — the same dataset that powers the Tavita app. They were independently re-verified by blind re-derivation on August 9, 2026. See the methodology page for how this library is built and kept current.
Tavita is not a medical provider. This page is educational information, not medical advice — talk to your clinician before changing your supplement or medication routine.