The most common cause is poor intake, on a deficient diet, folate deficiency develops over the course of about 4 months - may develop rapidly in patients who have both poor intake and excess utilisation of folate (e.g. patients in ICU)

Management

• can be corrected giving 5mg folic acid daily, treatment should be given for 4 months to replace body stores
• any underlying cause (eg. coeliac disease) should be treated
• prophylactic folic acid (400 micrograms daily) for all women planning a pregnancy and in pregnancy
• Prophylactic folid acid of 5mg (daily or weekly) is given to patients with chronic haemotological disorders where there is rapid cell turnover and those undergoing renal dialysis