Iron absorption occurs from

Almost all iron absorption occur in duodenum & upper jejunum (proximal small intestine). Absorption of the majority of nutrients takes place in the jejunum, with the following notable exceptions: Vitamin B12 and bile salts are absorbed in the terminal ileum. Water and lipids are absorbed by passive diffusion throughout the small intestine. Sodium bicarbonate is absorbed by active transport and glucose and amino acid co-transport. Fructose is absorbed by facilitated diffusion.