Vitamin B1 (Thiamine)
Body function
Converts carbohydrates into energy; supports nerve and heart function
Daily requirement
~1.1 mg/day (women), ~1.2 mg/day (men)
Deficiency signs
Fatigue, irritability, poor memory, nerve tingling; severe deficiency causes beriberi
Excess risks
Low risk; excess is excreted in the urine
At-risk groups
Heavy alcohol users, people with poor diets, some after bariatric surgery
Supplement forms
Thiamine hydrochloride or mononitrate; benfotiamine (a fat-soluble form)
Food sources
- Lentils (cooked) — ~0.3 mg per cup cooked
- Pumpkin seeds — ~0.1 mg per 30g serving
- Pistachios — ~0.2 mg thiamine per 30g
- Flax seeds — ~0.5 mg thiamine per 30g
- Macadamia nuts — ~0.3 mg thiamine per 30g
- Sunflower seeds — ~0.4 mg thiamine per 30g
- Corn — ~0.3 mg thiamine per cup
Related symptoms
Educational information only — not medical advice. This content does not diagnose, treat, or replace consultation with a qualified healthcare professional. Always seek professional medical advice for symptoms, supplement use, or health concerns.