Final answer:
Iron absorption can be negatively affected by dietary substances like phytic acid and medical conditions. Acidic pH of the gastrointestinal tract favors iron absorption, while alcohol can enhance it. The absorption process mainly takes place in the duodenum and the jejunum.
Step-by-step explanation:
Factors that interfere with the absorption of iron are multifaceted, involving dietary components, physiological conditions, and medical procedures. Iron absorption is significantly hampered by substances like phosphate, phytic acid, and oxalic acid, which form insoluble complexes with iron. Anemic individuals might absorb more iron compared to those with normal iron saturation due to their body's higher demand. Medical conditions such as pernicious anemia and hypoplastic anemia also increase iron absorption. On the other hand, iron absorption is impaired in individuals who have undergone a total gastrectomy or significant bowel resection. Furthermore, the presence of an acidic environment in the gastrointestinal tract is crucial for optimal iron absorption, as it aids in the reduction of ferric iron to a more soluble ferrous state. Achlorhydria, the use of antacids, and copper deficiency are known to diminish iron absorption. Interestingly, alcohol ingestion can enhance iron absorption.
Iron uptake occurs primarily in the duodenum and the proximal jejunum, with the body's total iron pool receiving iron upon its absorption. Efficient absorption of heme iron, found in animal sources, is contrasted with less efficient absorption of non-heme iron from plant sources. Consequently, excessive iron intake can disrupt the absorption of other minerals, such as calcium and phosphorus. The body regulates iron uptake by utilizing various proteins like transferrin and ferroportin, both of which are crucial in the transportation and storage of iron within the body.