Folic acid deficiency may be due to an unbalanced diet. Alcoholics are potential candidates for this type of deficiency. The deficit can occur in women during pregnancy, the elderly, in people who are on a low-calorie diet, in patients with sickle cell anemia or other blood disorders, in cases of vitamin B12 deficiency, in people who have problems with weak absorption in the small intestine and in patients using various drugs (such as, drugs based on phenobarbital, primidone, and oral contraceptives).
Lack of vitamin B9 may cause anemia, which is similar to that occur in the absence of vitamin B12 (so called megaloblastic anemia), and leukopenia (distortion of synthesis of white blood cells), and changes in metabolism.
Lack of folic acid in mammals cause growth problems.
Other symptoms that may occur in the absence of folic acid are general body weakness, fatigue, irritability and stomach aches.
Disorder in absorption of folic acid occurs in idiopathic steatorrhea (disorder in the absorption of dietary fat) and tropical sprue (a disease with weak absorption in the intestine, occurs in the tropics), as well as various other disorders of the small intestine.
Overdose (hypervitaminosis, intoxication)
Vitamin B9 is toxic in excessive doses and can cause serious neurological problems.