Which nutrient is absorbed in the duodenum?

The duodenum, which is the first section of the small intestine immediately following the stomach, plays a critical role in the digestion and absorption of various nutrients. Iron is one such nutrient that is predominantly absorbed in the duodenum.

Iron absorption is facilitated by the acidic environment created by gastric juices, which help convert iron into a more soluble form that can be absorbed. In the duodenum, specific transport proteins and mechanisms are involved in taking up heme iron (from animal sources) and non-heme iron (from plant sources). The presence of ascorbic acid (vitamin C) in the diet can enhance the absorption of non-heme iron by reducing it to a form that is more readily absorbed.

While other nutrients listed are absorbed in various areas of the intestines, iron's primary absorption occurs in the duodenum, making it the correct answer in this context.