Vitamin B9 Deficiency

General text about the lack of vitamins can be found here.


Vitamin B9 is also known as folic acid (folate). Our body can not produce this substance and we must therefore take it in food. It is a substance of great importance as it participates in many enzymatic reactions in our body. It is significant in metabolism of proteins and synthesis of DNA and RNA that are necessary for formation of new cells (very important in hematopoiesis and in development of human embryo). Like other vitamins of the B complex folic acid is present in large quantities in yeast and in leafy vegetables (spinach, kale and broccoli).


Deficiency of folic acid is usually caused by low dietary intake, which is typical for chronic alcoholics. The lack of vitamin also occurs in patients with diseases of digestive tract related to malabsorption of nutrients and in patients attending chronic dialysis programme. Relative deficiency of folic acid may occur in pregnant women, who have increased need of this substance that is necessary for proper fetal development. A very specific problem is the lack of vitamin B9 in patients treated with drugs containing sulfasalazine.


Probably the most typical manifestation of folate deficiency is anemia, which develops due to impaired formation of new blood cells. In the blood count we find erythrocytes with abnormally large volume, which is similar to pernicious anemia (which occurs in vitamin B12 deficiency). The anemia manifests with signs of anemic syndrome. Other symptoms include mouth ulcers, brittle nails, loss of appetite, diarrhea, headache and palpitations.


Due to the fact that folic acid is necessary for development of the human fetus, its deficiency in pregnancy is associated with more frequent occurrence of congenital defects (e.g. split spine).


Folic acid level may be easily measured in a laboratory from a sample of venous blood. If the reason for the examination is anemia with large blood cells, it is also advisable to measure the blood level of vitamin B12.


Folate may be administered as a dietary supplement in form of tablets; its increased income is mainly needed in pregnant women. Overdose by folate is virtually impossible as the vitamin is easily and rapidly excreted into the urine.


Jiri Stefanek, MD  Author of texts: Jiri Stefanek, MD
 Sources: basic text sources