Low serum folate is defined as below the lower end of the normal range. Serum folate levels can fluctuate according to recent dietary intake. Levels at the lower end of the normal range may still suggest deficiency. The most helpful investigation is a dietary history.
Effects include glossitis, macrocytic anaemia, neuropathy.
Folate is present in leafy vegetables and fruit. It is not stored and is destroyed by overcooking. Dietary deficiency is thus extremely common.
Folate and iron are absorbed in jejunum so combined deficiency is very suggestive of Coeliac disease or inflammatory bowel disease.
Folate can be stopped if there is an obvious temporary dietary cause of deficiency.
C.M & L.W 24-7-26
Who to refer:
- Patients not responding haematologically to replacement therapy.
- Patients with suspected malabsorption or disease of the terminal ileum should be referred to Gastroenterology.
Who not to refer:
Uncomplicated folate deficiency
How to refer:
SCI Gateway to Department of Haematology RIE, WGH and SJH
Primary care investigations
- FBC
- Ferritin
- Serum folate and B12
- Coeliac screen, unless definite dietary cause.
- If symptoms of inflammatory bowel disease, then LFTs, albumin, and CRP may be helpful.
- CKS summary on Anaemia: B12 and folate deficiency
- Patient information including dietary advice: https://www.bda.uk.com/resource/folic-acid.html












