Which vitamin deficiencies are associated with macrocytic anemia?

Which vitamin deficiencies are associated with macrocytic anemia?

• A. Folic acid
• B. Vitamin B12
• C. Both Folic acid and Vitamin B12
• D. Niacin

Answer: (C)

Macrocytic anemia comes from impaired DNA synthesis in red blood cell precursors, causing the cells to grow larger without dividing properly. Folate and vitamin B12 are both essential for DNA synthesis; a deficiency in either disrupts thymidine production, leading to megaloblastic, oversized erythroid cells and macrocytosis. Therefore, deficiencies of both folic acid and vitamin B12 are associated with macrocytic anemia. Niacin deficiency causes pellagra (dermatitis, diarrhea, dementia) and is not linked to macrocytosis, so it doesn’t explain this type of anemia.

Macrocytic anemia comes from impaired DNA synthesis in red blood cell precursors, causing the cells to grow larger without dividing properly. Folate and vitamin B12 are both essential for DNA synthesis; a deficiency in either disrupts thymidine production, leading to megaloblastic, oversized erythroid cells and macrocytosis. Therefore, deficiencies of both folic acid and vitamin B12 are associated with macrocytic anemia. Niacin deficiency causes pellagra (dermatitis, diarrhea, dementia) and is not linked to macrocytosis, so it doesn’t explain this type of anemia.