Folic Acid Deficiency

At a glance

Folic acid is a B-complex vitamin that is essential for protein synthesis and erythropoiesis. Megaloblastic anemia resulting from folic acid deficiency secondary either to dietary deficiency or malabsorption syndrome. A genetically transmitted disorder with poor prognosis unless folinic acid is regularly administered. Patients with folate deficiency and elevated homocysteine (Hcy) levels have increased risk of cerebrovascular and cardiovascular disease.

Synonyms

Congenital Folate Malabsorption; Hereditary Folate Malabsorption; Transport Defect Involving Folic Acid.

Genetic inheritance

Not well identified. Twenty cases of this rare disorder have been reported in the literature. There is a predominance for females; however, it is also reported that males can also be affected to a lesser degree.

Pathophysiology

Folic acid is reduced by dihydrofolate reductase to form tetrahydrofolate. Tetrahydrofolate is important in one carbon transfer reaction and essential in the methylation of deoxyuridylate to thymidylate during DNA synthesis. This leads to megaloblastic anemia, although the mechanism is poorly understood in nutritional diseases. Folic acid deficiency is caused by dietary deficiency, impaired absorption, or increased requirements. Nutritional deficiency is seen in the elderly, alcoholics, premature infants, infants raised on goat’s milk and in hemodialysis, hyperalimentation, and gastrectomy patients. Impaired absorption occurs in sprue, regional enteritis, after extensive small bowel resections, in Whipple disease, and in leukemic infiltration of the intestine. Increased requirements are seen in pregnancy and in diseases with increased cell turnover, such as hemolytic anemia.

Diagnosis

Clinical signs and symptoms are those of chronic anemia. Onset is insidious and associated with weakness, palpitation, fatigue, light-headedness, and dyspnea. Pallor and jaundice are common. Leukocyte and platelet counts may be depressed. Laboratory features include low serum and red cell folate, low reticulocyte count, macrocytic anemia, and hypersegmented neutrophils. Bone marrow examination reveals erythroid megaloblastic changes.

Clinical aspects

Hereditary form manifests as recurrent megaloblastic anemia, mental retardation, convulsions, movement disorder (ataxia), diarrhea, susceptibility to infections, and calcification of basal ganglia. Most patients die within the first few months of life as a consequence of diarrhea, vomiting, drowsiness, pallor, and glossitis.

Precautions before anesthesia

Patients with folate deficiency and elevated homocysteine (Hcy) levels have increased risk of cerebrovascular and cardiovascular disease. Check hematocrit. Elective surgery is contraindicated until anemia resolves with treatment. In hereditary forms, avoid anesthesia unless there is a life-threatening surgical indication. Most infants are in very poor physical status with malnutrition and chronic dehydration. Check carefully fluid losses and avoid both underinflation and overinflation of fluids (intraoperatively and postoperatively). Provide IV folic acid and consider prophylactic antibiotics. Check acid balance status and plasma protein levels.

Anesthetic considerations

No specific anesthetic consideration with this condition except for potential severe anemia and epilepsy ...