Folate deficiency Diagnosis and management CBC and peripheral blood smear Q Does peripheral blood smear show oval macrocytes? Q Does peripheral blood smear show hypersegmented neutrophils? Q Does CBC show an elevated MCV? Yes to any Consider suspecting cobalamin or folate deficiency in patients in whom blood film shows oval macrocytes and hypersegmented neutrophils in the presence of an elevated MCV. C Folate supplementation Treat folate deficiency according to the following schedules : due to dietary insufficiency, pregnancy, or antiepileptics: folic acid 5 mg PO daily for 4 months due to malabsorptive states: consider folic acid 15 mg PO daily for 4 months. A Continue folic acid supplementation until term in pregnant patients. No to all Indications for testing Q Are there other reasons to suspect folate deficiency? Yes Test for folate deficiency in clinical situations similar to those in which testing for cobalamin deficiency is obtained. A No Serum folate and cobalamin Obtain cobalamin and folate assays concurrently, given the close relationship in their metabolism. A Diagnostic criteria Q Is serum folate level <7 nmol/L (3 g/L)? Yes Recognize that a serum folate level < 7 nmol/L (< 3 g/L) is indicative of folate deficiency. B No Red blood cell folate Avoid routine testing of RBC folate, since serum folate alone is sufficient in most cases. D Consider RBC folate assays in patients in whom serum folate is normal yet folate deficiency is strongly suspected, after having excluded cobalamin deficiency. C Vitamin B12 supplementation Without neurological involvement Q Does the patient have neurological involvement? Yes Consult with pharmacy references to clarify any suspicion of low serum folate levels associated with prescribed medications. No Vitamin B12 supplementation, with neurological involvement Administer vitamin B12 (1,000 g IM every 2 days until clinical improvement ceases) for the treatment of patients with neurological involvement. A Consider reviewing the need for continuation of alternate day therapy after 3 weeks of treatment. Folate supplementation Treat folate deficiency according to the following schedules : due to dietary insufficiency, pregnancy, or antiepileptics: folic acid 5 mg PO daily for 4 months due to malabsorptive states: consider folic acid 15 mg PO daily for 4 months. A Continue folic acid supplementation until term in pregnant patients. 