This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
[{'content': 'In which of the following conditions is the synthesis of hepcidin not reduced ? \nSelect and explain. \nA. Hypoxia, B. Anemia, C. Hemorrhage, D. Hemosiderosis', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Inorganic iron is transported into the mucosal cell by a proton-linked divalent metal ion transporter, and accumulated intracellularly by binding to ferritin. Iron leaves the mucosal\xa0cell\xa0via\xa0a\xa0transport\xa0protein\xa0 ferroportin,\xa0but\xa0only\xa0if there is free transferrin in plasma to bind to. Once transferrin is saturated with iron, any that has accumulated in the mucosal cells is lost when the cells are shed. Expression of the ferroportin gene (and possibly also that for the divalent metal ion transporter) is downregulated by hepcidin, a peptide secreted by the liver when body iron reserves are adequate.\nIn response to hypoxia, anemia, or hemorrhage, the synthesis of hepcidin is reduced, leading to increased synthesis of ferroportin and increased iron absorption. As a result of this mucosal barrier, only ∼10% of dietary iron is absorbed, and only 1% to 5% from many plant foods.\nHemosiderosis is an iron overload condition and further iron absorption is not required.\nHARPERS ILLUSTRATED BIOCHEMISTRY30th ed. page no.541', 'role': 'assistant'}]