The daily intake of vitamin B1 is 1.0-1.5 mg. Vitamin B1 is mainly found in the outer skin of seeds and germ, and can be lost in large quantities in overly processed grains. Vitamin B1, also known as thiamin, is absorbed in the small intestine and is mainly transformed into active TPP, a coenzyme of alpha-keto acid oxidative decarboxylase, also known as thiamin pyrophosphate, which is also a coenzyme of transketolase. When the body is deficient in vitamin B1, it can develop foot disease, which can lead to peripheral neuritis, loss of appetite, or the occurrence of swelling and neuromuscular degeneration.