<prompt> Megaloblastic anemia is caused byB6ThiamineFolic acidRiboflavin  <response>: C. i.e. Folic acid 377- Harsh Mohan 5th 437- Basic pathology 8thMEGALO BLASTIC ANEMIAS - two principal causes1. Folate deficiency Folic acid metabolism2. Vitamin B12 deficiency Earliest change in PBS is appearance of hypersegmented neutrophils Bone marrow is markedly hypercellular Macrocytosis other causes - Haemolysis, liver disease, alcoholism, hypothyroidism, aplastic anaemia, myeloproliferative disorders and reticulocytosis MCV , MCH, MCHC Normal or SHILLING TEST for Vitamin Bj2 deficiency FIGLU TEST for folate deficiency The gene responsible for folic acid transport is situated on chromosome 21 