Vitamin B1, also called thiamin or thiamine, is a water-soluble B vitamin found in many types of food. Good sources include peas, some fresh fruit such as bananas and oranges, nuts, wholegrain breads, pork and some fortified breakfast cereals. Thiamin cannot be stored in the body, so you need it in your diet every day, but most people get all they need from a varied, balanced diet.
Thiamin helps the body break down and release energy from food and helps keep the nervous system healthy. It contributes to normal energy-yielding metabolism and to the normal function of the heart, which is why it sits at the centre of most B-complex and energy formulas.
On supplement labels thiamin usually appears as thiamin mononitrate or thiamin hydrochloride, both stable forms that suit tablets and capsules. Some products use benfotiamine, a synthetic form of thiamin. You will find it in multivitamins, B-complex products and single-nutrient supplements, with the amount listed in milligrams (mg).