Hematology
Anemia
Folate deficiency anemia

Author: R. Amita, M.D., D.N.B. (see Authors page)

Revised: 25 August 2016, last major update August 2016

Copyright: (c) 2016, PathologyOutlines.com, Inc.

PubMed Search: Folate deficiency anemia [title]

Cite this page: Folate deficiency anemia. PathologyOutlines.com website. http://pathologyoutlines.com/topic/hematofolatedefanemia.html. Accessed April 28th, 2017.
Definition / general
  • Folate deficiency is a low level of folic acid (Vitamin B9) in the body
Essential features
  • Characterized by macrocytic anemia
Terminology
  • Also called Vitamin B9 deficiency
Pathophysiology
Etiology
  • Inadequate ingestion of folate containing foods due to: alcoholism (alcohol dehydrogenase binds folate), psychiatric morbidities, elderly
  • Impaired absorption: celiac disease, tropical sprue, achlorhydria, anticonvulsant drugs (Dilantin), zinc deficiency, bacterial overgrowth in blind loops, strictures, jejunal diverticula
  • Impaired metabolism, leading to inability to utilize absorbed folate: methotrexate and trimethoprim (folate antagonists)
  • Hypothyroidism (decreases hepatic levels of dihydrofolate reductase)
  • Congenital deficiency of enzymes of folate metabolism
  • Increased requirement: infancy, pregnancy, lactation, malignancy, concurrent infection (immunoproliferative response), chronic hemolytic anemia (increased hematopoiesis)
  • Increased excretion/loss: vitamin B12 deficiency (causes "folate trap"), chronic alcoholism (increased excretion of folate into bile), hemodialysis (may have excess folate loss)
  • Increased destruction: superoxide can inactivate folate
Clinical features
  • Symptoms due to anemia: weakness, fatigue, difficulty concentrating, irritability, headache, palpitations, shortness of breath, cardiac failure
  • Gastrointestinal symptoms: anorexia, nausea, vomiting, abdominal pain, diarrhea (especially after meals)
  • Neurologic: cognitive impairment, dementia, depression

Complications:
  • Coronary artery disease, stroke
  • Pregnancy complications include spontaneous abortion, abruption placentae, congenital malformations (neural tube defects), severe language delay
Diagnosis
  • Serum folate levels < 3 ng/mL and a red blood cell (RBC) folate level < 140 ng/mL indicate folate deficiency
  • Normal serum folate level is 2.5-20 ng/mL
  • Normal serum cobalamin is 200-900 pg/mL
Laboratory
  • The RBC folate level generally indicates folate stored in the body
  • Serum folate level tends to reflect acute changes in folate intake
  • Mild hyperhomocystinemia is total plasma concentration of 15-25 mmol/L; moderate hyperhomocystinemia is 26-50 mmol/L
Case reports
Treatment
  • Important to rule out cobalamin (Vitamin B12) deficiency because folate treatment will not improve neurologic abnormalities due to cobalamin deficiency
Microscopic (histologic) description
  • Bone marrow biopsy and aspirate may show a hypercellular bone marrow with a megaloblastic maturation of cells, which morphologically resembles changes of vitamin B12 deficiency
Microscopic (histologic) images
Images hosted on other servers:

Megaloblastic erythroid precursors

Hypersegmented
neutrophils,
macro ovalocytes

Virtual slides
Images hosted on other servers:

Hematology Atlas

ASH - Image bank