Vitamin B₁

Vitamin B₁ (thiamin) is present in a variety of food sources, including whole grains, nuts, legumes (beans and dried peas), and pork. It works in unison with other B vitamins to convert the energy in the foods we consume to muscular energy and heat. Thiamin contributes to this metabolic process by removing carbon dioxide in energy reactions with its active coenzyme thiamin pyrophosphate (TPP), an enzyme that is particularly important in carbohydrate energy metabolism.

Thiamin deficiency has not been reported in athletes, but deficiency disease does occur in alcoholics and populations consuming a low-quality diet of unenriched polished rice or other processed and unenriched grains. The DRI for thiamin (1.2 milligrams per day for males, 1.1 milligrams per day for females) may be inadequate for athletes. The actual requirement is based on approximately .5 milligrams of thiamin for each 1,000 calories consumed, and athletes often consume more than 3,000 calories (often 5,000 to 6,000 calories). It does appear that the upper limit for thiamin intake would be 3.0 milligrams per day, even for an athlete consuming more than 6,000 calories per day. It is reasonable, therefore, to recommend an intake of two times the DRI (~2.2 to 2.4 milligrams per day) for athletes consuming high levels of energy. Athletes commonly consume high-carbohydrate foods that are good sources of thiamin, making it likely that most well-nourished athletes already consume more than the recommended level of thiamin each day.