Megaloblastic anemia should be treated with both folic acid and vitamin B12 because:
**Core Concept**
Megaloblastic anemia is a type of anemia characterized by the production of abnormally large red blood cells that are not able to function properly. This condition is often caused by a deficiency in either vitamin B12 or folate, which are essential for DNA synthesis and cell division.
**Why the Correct Answer is Right**
The correct answer is that both folic acid and vitamin B12 should be administered to treat megaloblastic anemia because they work synergistically to support DNA synthesis. Folate is required for the conversion of homocysteine to methionine, while vitamin B12 is necessary for the conversion of homocysteine to methionine and for the synthesis of methylene-tetrahydrofolate (mTHF) from 5,10-methylene-tetrahydrofolate. If either folate or vitamin B12 is deficient, DNA synthesis is impaired, leading to the production of abnormal red blood cells.
**Why Each Wrong Option is Incorrect**
* **Option A:** Folic acid alone is not sufficient to treat megaloblastic anemia because it can mask the neurological symptoms of vitamin B12 deficiency, leading to irreversible damage if left untreated.
* **Option B:** Vitamin B12 alone is not sufficient to treat megaloblastic anemia caused by folate deficiency, as folate is necessary for the conversion of homocysteine to methionine.
* **Option D:** Iron supplementation is not effective in treating megaloblastic anemia, as the underlying cause is a deficiency in vitamin B12 or folate, not iron.
**Clinical Pearl / High-Yield Fact**
It's essential to note that folic acid can mask the neurological symptoms of vitamin B12 deficiency, so it's crucial to administer both vitamins to prevent irreversible damage.
**Correct Answer: C. Both folic acid and vitamin B12 should be administered to treat megaloblastic anemia because they work synergistically to support DNA synthesis.**