NOT true regarding Iron metabolism
**Core Concept**
Iron metabolism is a complex process involving absorption, transport, storage, and utilization of iron in the body. It is crucial for the synthesis of hemoglobin, myoglobin, and various enzymes.
**Why the Correct Answer is Right**
Iron absorption occurs primarily in the duodenum and proximal jejunum, where it is taken up by enterocytes via the divalent metal transporter 1 (DMT1). The absorbed iron is then transported to the liver, where it is stored in the form of ferritin. The stored iron is released into the bloodstream as needed, bound to transferrin, and transported to various tissues for utilization. The regulation of iron metabolism involves the hepcidin-ferroportin axis, where hepcidin is a hormone produced by the liver that inhibits iron export from enterocytes and macrophages.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify a true statement about iron metabolism. To be a correct distractor, it would need to contain a false statement about iron metabolism.
**Option B:** This option is incorrect because it does not accurately describe the primary site of iron absorption in the gastrointestinal tract. While the duodenum and proximal jejunum are involved in iron absorption, the stomach is also a significant site of iron absorption, particularly non-heme iron.
**Option C:** This option is incorrect because it does not accurately describe the regulation of iron metabolism. While hepcidin is a hormone that regulates iron metabolism, it is not the primary regulator of iron utilization in the body.
**Option D:** This option is incorrect because it does not accurately describe the storage of iron in the body. While ferritin is a protein that stores iron, it is not the only form of iron storage in the body.
**Clinical Pearl / High-Yield Fact**
Hepcidin is a hormone produced by the liver that regulates iron metabolism by inhibiting iron export from enterocytes and macrophages. An understanding of hepcidin's role in iron metabolism is crucial for diagnosing and managing iron-related disorders, such as hemochromatosis and iron deficiency anemia.
**Correct Answer: B. The stomach is a significant site of iron absorption, particularly non-heme iron.**