Folic acid is the synthetic form of folate and these compounds are collectively known as vitamin B9. Vitamin B12 and folate occur naturally in foods. All of these effects lead to a deficiency in red blood cells, hence the term megaloblastic anemia. Hemolysis (red blood cell rupture and destruction) also occurs for no known reason in megalobalstosis. Megaloblastic cells also have a fragile cell membrane and rupture easily due to various stresses a red blood cell experiences in its life cycle. These oversized cells known as megaloblasts may undergo apoptosis (a self-orchestrated death) before it even leaves the bone marrow. Effect of Abnormally Enlarged Red Blood Cells

However it is important to realise that the abnormality in shape and size is evident throughout the stages of development from a hematopoietic stem cell to a mature red blood cell. In the final stages of maturation, vitamin B12 (cobalamin) and folate (folic acid) is required and a deficiency of these nutrients gives rise to megaloblastic anemia. Over a period of 7 days these cells undergo various stages of development until the mature red blood cell is released into circulation. Red blood cells are manufactured in the bone marrow from hematopoietic stem cells. This enlargement of the neutrophils is an important diagnostic indicator of megaloblastic anemia. Neutrophils, a type of leukocyte (white blood cell), is also enlarged with more than the three to four nuclear lobules it normally has. The abnormally large shape is evident from the early stages of development while the cell is still an immature precursor. In a person with megablastosis, the red blood cells vary significantly in size ( anisocytosis) and in shape ( poikilocytosis) compared to the constant and regular shape and size of normal red blood cells. Megaloblastic anemia is a group of disorders characterized by abnormally large red blood cells. Different diseases can change many physical features of these red blood cells, thereby distorting its shape and size. Its size and flexibility allows it to pass or squeeze through even the smallest of blood vessels. On average, a red blood cell is about 7.8um in diameter and 2um thick. The cells are disc shaped with a central depression – the thickness in the middle is about 1um while at outer edges it is about 2.5um. These cells measure about 6 to 8 micrometers (um) in diameter which is equivalent to 0.006 to 0.008 millimeters – too small to be seen by the naked eye. Red blood cells (RBCs) or erythrocytes are small round cells that circulate in the blood stream and carry oxygen throughout the body.

Anemia with misshapen red blood cells