Snapshot A 25-year-old woman presents to her obstetrician at 22-weeks pregnant. She had no previous prenatal care but denies any problems. She denies taking any vitamin supplements. She is doing well in her first pregnancy and finally came for prenatal care at the urging of her mother. She is notably pale. Bloodwork reveals megaloblastic anemia and she is started on folic acid supplementation immediately. However, she is counseled on the possible affects folic acid deficiency may have on the baby. Introduction Folic acid (or vitamin B9) is found in leafy green vegetables Pathogenesis folic acid is absorbed in jejunum and ileum used in tetrahydrofolate (THF) as coenzyme important for DNA and RNA synthesis small reserve pool in liver see Vitamins topic causes megaloblastic anemia due to impaired DNA synthesis Epidemiology most common vitamin deficiency in the US most common cause of megaloblastic anemia can manifest after 4 months (depleted storage from liver) Associated conditions chronic hemolytic anemias alcoholism malabsorption celiac disease tropical sprue pregnancy risk of neural tube defects in infant certain drugs (anti-folates) phenytoin methotrexate Presentation Symptoms no neurological symptoms (unlike in B12 deficiency) anemia fatigue weakness shortness of breath Physical exam glossitis pallor Evaluation Peripheral blood smear hypersegmented lobes seen in neutrophils macrocytosis Serum ↓ folic acid ↑ homocysteine NORMAL methylmalonic acid (MMA) unlike in vitamin B12 deficiency, which has ↑MMA Differential Diagnosis Vitamin B12 deficiency Pernicious anemia Other causes of macrocytic anemia alcoholism hypothyroidism liver dysfunction drugs Treatment Folic acid supplementation Eat a more balanced diet fruits and vegetables Prognosis, Prevention, and Complications Prognosis good with supplementation Prevention folic acid supplementation, especially if chronically on drugs such as methotrexate Complications neural tube defects in infant if deficient during pregnancy