treatment of folate deficiency

Last reviewed 09/2022

Blood transfusion for folate deficiency is rarely indicated except in severe anaemia or where other causes of anaemia, such as bleeding, coexist.

Transfusion carries the danger of fluid overload, especially in the elderly.

A suggested management for folate deficiency (measured via red cell folate) is (1):

• refer to exclude malabsorption or chronic inflammatory states if red cell folate levels particularly low and dietary deficiency unlikely
• "..With borderline levels a response to physiological levels of folic acid may be diagnostic of dietary deficiency..."

When administering replacement therapy (2,3):

Folic acid is given orally. There are few indications for long-term therapy since most causes of folate deficiency are self-limiting or will yield to a short course of treatment. Folic acid should not be used alone for pernicious anaemia and other vitamin B12 deficiency states because this may precipitate subacute combined degeneration of the cord.

• in folate-deficient megaloblastic anaemias (e.g. due to poor nutrition, pregnancy, or antiepileptics), standard treatment to bring about a haematological remission and replenish body stores, is oral administration of folic acid 5 mg daily for 4 months; up to 15 mg per day may be required in malabsorption states
• the raised MCV may take time to correct because of the normal 120-day red cell turnover
• also patients should be encouraged to increase their dietary intake
• it is important that serum B12 levels are normal because treatment with folic acid can precipitate subacute combined degeneration of the cord
• the need for maintenance folic acid will be dependent on cause
• potassium or iron deficiency may occur in the recovery phase after folate therapy in the treatment of a folate-deficient megaloblastic anaemia; supplements should be administered as required.

Reference:

1. Pulse (2004);64 (35):88.
2. BNF 9.1.2
3. Pulse (2003); 63 (6): 84.