Thiamin
Helps your cells turn carbohydrates into usable energy.
Why it matters
Thiamin helps cells turn carbohydrates into energy and is important for normal nerve, muscle, and heart function.
- Supports energy metabolism.
- Helps nerves, muscles, and the heart function properly.
- Acts as a cofactor for several enzyme systems.
If intake is too low
Thiamin deficiency can affect the nervous system and the heart. Severe deficiency causes beriberi, and a related brain disorder called Wernicke-Korsakoff syndrome is strongly linked with alcohol use disorder.
- Loss of appetite, weight loss, confusion, and memory problems.
- Muscle weakness and nerve symptoms.
- Heart-related complications in more severe deficiency.
If intake is too high
No known adverse effects from high thiamin intakes have been established, and no upper limit has been set.
- No established upper limit.
- No clear toxicity pattern has been identified in healthy people.
- More is not automatically useful if you already meet your needs.
No adult upper limit established
No tolerable upper intake level has been established because harmful effects from excess thiamin have not been confirmed.
Common food sources
Thiamin is widely available in pork, legumes, and fortified grain products.
- Pork and trout
- Beans, lentils, and peas
- Fortified breads, cereals, rice, and noodles
Who may need closer attention
Low thiamin becomes more likely when calorie intake is poor, alcohol intake is high, or absorption is impaired.
- People with alcohol use disorder
- Anyone with very low food intake or severe illness
- People after bariatric surgery or with chronic absorption problems
Use extra caution if
Small details change the risk picture with nutrients more than most people expect.
You drink heavily, have limited food intake, or have a condition that affects nutrient absorption. Thiamin deficiency matters most when intake stays low for a while.
Supplement and label notes
Useful context when this nutrient shows up across more than one product.
- Thiamin is common in B-complex formulas, multis, and some energy-focused blends.
- Deficiency is the main concern with thiamin; megadosing is usually unnecessary if intake is already adequate.
- When appetite is poor or alcohol use is high, low thiamin matters more than subtle differences in supplement form.
Daily Value targets in SuppMap
These are the same label-style Daily Value targets used in the app.
Official references
These pages were used to draft the summaries on this guide.
Educational only. These pages are not a diagnosis or a substitute for personal medical care.
More guides
Keep moving through the rest of the Daily Value chart from here.