Vitamins B1

Vitamin B1: Absorbed mainly from duodenum, the total amount which can be absorbed is 4 to 8 mg. Body stores are approximately 30 mg. Storage is mainly in skeletal muscles, heart, liver, kidneys and brain, it is metabolized in the liver and excreted in the urine.
Vitamin B6: Absorbed from the gastrointestinal tract, converted to the active forms of vitamin B6 and stored in the liver and brain. Total body stores amount is 16 to 27 mg, it is metabolized in the liver and excreted in the urine.
Vitamin B12: Absorbed in the stomach by combination with the Intrinsic factor, the complex is absorbed in the terminal ileum, it is stored in the enterohepatic circulation and is excreted in small quantities in the urine, approximately 56% 1 mcg oral dose of Vitamin B12 is absorbed.