Megaloblastic anaemia due to folic acid deficiency occurs commonly among pregnant women and to a lesser extent in preschool children. It occurs due to presence of low amount of B 12.
The RBC count is low 2-3 millions per mm3 and haemoglobin is 6-9%. The diameter of the RBC is greater than normal and hence the anaemia is called macrolytic anaemia. Examination of the bone marrow aspirate reveals the presence of characteristic megablasts, indicating that maturation of the RBC is affected in folic acid deficiency.
The clinical signs are similar to those observed in iron deficiency anaemia. Patients with anaemia have lemon yellow or pale skin. Anorexia, achlorhydria, abdominal discomfort, weight loss and general weakness can also occur. Clinical manifestations are mental apathy, pigmentation, growth retardation and megaloblastic bone marrow. In young females there may be infertility.
Well balanced-diet providing all dietary requirements should be given. If haemoglobin level is under 4 g/dl blood transfusion should be always given. Physical activity should be at minimum until the haemoglobin is above 7 g/dl. Hydroxocobalmin should be given in a dosage of 100 mcg intramuscularly twice during first week, then 250 mcg weekly should be given until the blood count is normal. Then 1000 mcg for every 6 weeks is given. Diets varies according to age groups.
Folic acid (1-2 mg) orally daily, ferrous ammonium sulphate mixture to provide 6 mg iron per kg body weight daily is given for a period of 1 month or longer till the anaemia is cured.
Folic acid 5 mg once daily and ferrous sulphate tablets (0.2 g) twice daily for 10 days and folic acid 2 mg and ferrous sulphate (0.2 g) twice daily from 11th day to 40th day should be given.