The most common cause of folate deficiency is insufficient dietary intake and is frequently found in pregnancy and alcoholics. It is useful in evaluating macrocytic megaloblastic anaemia. Other causes of deficiency may include liver disease, some drugs, malabsorption syndromes, and malignancies. RBC Folate levels are not quite as dependent on present dietary intake and is a better measurement of tissue folate stores than serum folate. Vitamin B12, Folate and RBC Folate levels run together are the most meaningful.