Malnutrition, alcohol abuse, pregnancy, a history of sprue, severe psoriasis, or the use of antiseizure drugs may indicate a folic acid deficiency. Often, vitamin B deficiencies cannot be determined by a history or symptoms alone. If a vitamin B12 deficiency is present and caused by pernicious anemia, a physician may not suspect this disease in patients whose diets are rich in folic acid. With folic acid now a required additive in many commercial foods, some experts are concerned that there will be an increased incidence of cases of undetected pernicious anemia. Tests for Megaloblastic Anemia .
Blood tests indicate megaloblastic anemia by revealing very large oval red blood cells.
They also may show abnormally shaped neutrophils, which are white blood cells. Bone marrow aspiration is usually not necessary but may be performed if the diagnosis is unclear. Determining Specific Vitamin Deficiencies and Pernicious Anemia. Once megaloblastic anemia has been diagnosed, the physician will need to determine what vitamin deficiency is causing it. Patients who have neurologic and psychiatric abnormalities with no detectable cause should still be tested for vitamin B12 deficiency, even if blood tests for megaloblastic anemia are normal.