Thiamin, or vitamin B1, is a water-soluble vitamin your body needs to turn carbohydrates into fuel. It works as a coenzyme in critical metabolic reactions throughout the body.
People often take thiamin to support energy production and help the body handle everyday stress. You can take it alone or inside a B-complex formula. Absorption improves when you take it with a meal.
The vitamin is safe for most people, but high supplement doses rarely do much unless you have a deficiency. Certain life situations, like heavy alcohol use or diabetes, can raise your need for thiamin. Very large doses sometimes cause mild stomach upset.