Vitamin B1 (thiamine)
Thiamine (thiamin)
Vitamins. Modern nutrition.
Also called Thiamin, Aneurin, Antiberiberi vitamin, Vitamin B-1
Pinyin: wéishēngsù B1
Spanish: Tiamina
A B vitamin the body uses to release energy from carbohydrates and to keep nerves and the heart working.
Did you know? In the 1890s, chickens fed polished white rice got a nerve disease like human beriberi, and rice bran helped them recover. The scientist who saw this, Christiaan Eijkman, shared a Nobel Prize in 1929.
What it may help, and how strong the proof is
- Nerve health. Thiamine deficiency causes beriberi, a disease that damages nerves and the heart. Thiamine clearly corrects it. Extra thiamine has not been shown to help nerves in people who get enough.Strong proof
- Memory & focus. Large doses are standard emergency care for Wernicke encephalopathy, a brain problem seen in heavy drinkers and in people who are badly malnourished. That proof comes mostly from case reports and clinical practice. Thiamine pills have not been shown to sharpen memory in healthy people.Early proof
- Energy & tiredness. Thiamine helps the body turn food into energy, so people assume extra thiamine gives more energy. In people who already get enough, it has not been shown to boost energy.Not supported
Parts of the body
Traditional use
Diets built on whole grains, beans and pork kept thiamine levels high for centuries. In the late 1800s, beriberi spread where people ate mostly polished white rice, and doctors had to find the cause.
How it is classified
How people take it
Adults need 1.2 mg a day (men) or 1.1 mg a day (women), the RDA or recommended daily amount. No upper limit has been set, because high doses from food and pills have not caused known harm. Hospitals give thiamine by IV for Wernicke encephalopathy, under medical care.
Food, tablet and capsule.
Where to get it
Good sources are lean pork, fortified breakfast cereals, enriched bread and rice, beans, lentils, peas, sunflower seeds, and whole grains. Nutritional yeast is very rich. Pills are sold as thiamine mononitrate or thiamine hydrochloride, alone or in B-complex blends.
Be careful
Thiamine is very safe from food and pills. IV doses have rarely caused allergic reactions, which is why hospitals give them slowly. Heavy drinking, vomiting, and long-term use of loop diuretics (water pills) can lower thiamine levels.
Avoid if: thiamine allergy (rare).
Mixing with other things
- Works well together
B vitamins work together in the energy steps of cells, and they are sold together in B-complex blends.
- Works well together
Both support nerve function and are often taken together in B-complex blends.
- Worth knowingAlcohol (beer, wine, spirits)
Heavy drinking lowers thiamine levels and raises the risk of thiamine-related brain problems.
- Worth knowingWater pills (furosemide, hydrochlorothiazide)
Loop water pills can increase thiamine loss in urine.
- Worth knowing
Horsetail may contain thiaminase, which can lower vitamin B1 if used heavily.
The honest take
Thiamine is a proven nutrient, and deficiency is serious. Heavy drinkers and people with poor diets are the most likely to need it. Claims that it adds energy or sharpens memory in people who already eat well are mostly hype.