Folate Deficiency Clinical Presentation

Updated: Jul 20, 2022
  • Author: Katherine Coffey-Vega, MD; Chief Editor: Emmanuel C Besa, MD  more...
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In folate deficiency, the patient's history is important because it may reveal the underlying reason for the deficiency. Very often, a patient presents with a history of excessive alcohol intake with concurrent poor diet intake. Other patients may be pregnant or lactating; may take certain drugs, such as phenytoin, sulfonamides, or methotrexate; may have chronic hemolytic anemia; or may have underlying malabsorption.

Some patients complain of a sore tongue or pain upon swallowing. The tongue may appear swollen, beefy, red, or shiny, usually around the edges and tips initially. Angular stomatitis also may be observed. These oral lesions typically occur at the time when folate depletion is severe enough to cause megaloblastic anemia, although, occasionally, lesions may occur before the anemia.

Patients may present with gastrointestinal (GI) signs and symptoms, such as nausea, vomiting, abdominal pain, and diarrhea, especially after meals. Anorexia also is common and, in combination with the above symptoms, may lead to marked weight loss. However, be aware that an underlying malabsorption disorder could be causing these symptoms, as well as folate depletion. The lack of folate itself may not be the culprit.

Neuropsychiatric presentations include cognitive impairment, dementia, and depression. These manifestations overlap with those of vitamin B12 deficiency.{ref50)


Physical Examination

Patients with folate deficiency may have darkening of the skin and mucous membranes, particularly at the dorsal surfaces of the fingers, toes, and creases of palms and soles. Distribution typically is patchy. Fortunately, the hyperpigmentation gradually should resolve after weeks or months of folate treatment.

A modest temperature elevation (< 102°F) is common in patients who are folate deficient, despite the absence of any infection. Although the underlying mechanism is obscure, the temperature typically falls within 24-48 hours of vitamin treatment and returns to normal within a few days.



Failure to provide folic acid supplementation to pregnant females may lead to spontaneous abortion and fetal abnormalities, including neural tube defects and increased risk of severe language delay in the child.

Providing only folic acid supplementation to a patient who has cobalamin deficiency may lead to development of irreversible neuropathies.