| Folic acid is a B vitamin needed for cell replication and growth. Folic acid helps form building blocks of DNA, the body’s genetic information, and building blocks of RNA, needed for protein synthesis in all cells. Folic acid plays an essential role in human growth and development, in particular cell division and DNA synthesis. The demand for folic acid increases when human cell growth is very active, such as in pregnancy, during breastfeeding, growth and some cancers e.g., leukaemias. Folate and folic
acid are forms of a water-soluble B vitamin. Folate occurs naturally in food. Folic acid is the synthetic form of this vitamin that is found in supplements and fortified foods. A deficiency of folate can occur when your need for folate is increased, when dietary intake of folate is inadequate, and when your body excretes (or loses) more folate than usual.
Folic acid deficiency is one of the most common nutritional deficiencies and has been observed in alcoholics, pregnant women, people living in institutions e.g. nursing homes, people with absorption problems such as ulcerative colitis and people taking certain medications e.g., methotrexate. In most cases a folic acid deficiency occurs without any symptoms. In severe cases of folic acid deficiency signs and symptoms such as macrocytic anaemia, weakness, tiredness, irritability, forgetfulness, difficulty breathing, anorexia, diarrhoea, weight loss, headache, palpitations and inflammation of the tongue may occur.
Signs of folic acid deficiency are often subtle. Diarrhea, loss of appetite, and weight loss can occur. Additional signs are weakness, sore tongue, headaches, heart palpitations, irritability, and behavioral disorders. Folic acid deficiency may cause poor growth, graying hair, inflammation of the tongue (glossitis), mouth ulcers, peptic ulcer, and diarrhea. It may also lead to certain types of anemias. Toxicity from excessive folic acid intake does not normally occur, as folic acid is water soluble and regularly excreted by the body. Folic acid deficiency causes macrocytic anemia in which the red blood cells are fewer in number, larger in size and contain less oxygen carrying hemoglobin than normal. The symptoms of anemia are lethargy, apathy, breathlessness, poor body temperature regulation, pallor, forgetfulness, irritability and stomach disorders. Folic acid deficiency affects the growth and repair of all the cells and tissues of the body. Cells that have the fastest rate of replacement are affected first.
A deficiency of folate can occur when an increased need for folate is not matched by an increased intake, when dietary folate intake does not meet recommended needs, and when folate excretion increases. Medications that interfere with the metabolism of folate may also increase the need for this vitamin and risk of deficiency. The elderly, alcoholics, psychiatric patients, epileptics and women taking the pill may be at greatest risk of folic acid deficiency. Prolonged stress, viral infections and chronic liver disease are also risk factors.
Folic acid deficiency during pregnancy increases the risk for neural tube defects including cleft palate, spina bifida, and brain damage. The requirement for folic acid increases considerably during pregnancy. Deficiencies of folic acid during pregnancy are associated with low birth weight and an increased incidence of neural tube defects in infants. Folate deficient women who become pregnant are at greater risk of giving birth to low birth weight, premature, and/or infants with neural tube defects. Neural tube defects are birth defects caused by abnormal development of the neural tube, a structure that eventually gives rise to the central nervous system (the brain and spinal cord). In infants and children, folate deficiency can slow growth rate. Some of these symptoms can also result from a variety of medical conditions other than folate deficiency. It is important to have a physician evaluate these symptoms so that appropriate medical care can be given.
Folic acid deficiency causes mood disorders and low levels may play a role in depression, possibly due to a reduction in neurotransmitter levels. People with ulcerative colitis and Crohn's disease (both inflammatory bowel diseases) often have low levels of folic acid in their blood cells. Folate deficiency appears to be linked to cervical dysplasia. A deficiency of folic acid has also been associated with peripheral vascular disease and coronary artery disease even in people with normal homocysteine levels. In addition, decreased blood levels of folic acid are associated with an increased risk of colon cancer in women. Alcohol interferes with the absorption of folate and increases excretion of folate by the kidney. In addition, many people who abuse alcohol have poor quality diets that do not provide the recommended intake of folate. Anti-convulsant medications such as dilantin increase the need for folate. Anyone taking anti-convulsants and other medications that interfere with the body's ability to use folate should consult with a medical doctor about the need to take a folic acid supplement. | 
