What nutrient is reabsorbed in the duodenum?

The correct answer is calcium. In the duodenum, an important part of the small intestine, significant reabsorption of nutrients occurs, and calcium is one of them. This mineral is absorbed primarily through two mechanisms: passive diffusion and active transport. The absorption process is facilitated by the presence of vitamin D, which enhances calcium uptake in the intestines.

Folate and vitamin B12, while important nutrients, are absorbed primarily in different regions of the gastrointestinal tract. Folate is mostly absorbed in the jejunum, and vitamin B12 absorption occurs mainly in the ileum, often requiring intrinsic factor for effective uptake. Iron is primarily absorbed in the duodenum as well, but its absorption is more closely associated with specific dietary conditions and the overall iron status of the body. Thus, while there can be some overlap in nutrient absorption in the duodenum, calcium is distinctly noted for its significant reabsorption at this point in the digestive process.