Lack of folic acid leads to anaemia. It is of value in the treatment of macrocytic anaemias, particularly those associated with metabolic diseases of the digestive system and and nutritional deficiencies. Neural tube defects (such as spina bifida) in foetuses are linked with a deficit of folic acid in the diet of the mother from the time of conception to the 12th week of pregnancy. To protect against spina bifida, it is estimated that pregnant women need three times the amount of folic acid normally occurring in their diet.
Folic acid is a B vitamin. It is available as a supplement and in some countries is also used to fortify some foods, such as bread and breakfast cereals. In 1945 it was synthesized by American workers, who suggested that the chemical name should be pteroylglutamic acid. Folic acid is also known as folate when it occurs naturally in a variety of foods such as brussels sprouts and broccoli, green beans, spinach and kale, oranges, cooked kidney, yeast and beef extracts, black-eye beans and certain other beans, vegetables and grain products. Over-cooking destroys folic acid. Folic acid is not stored in the body; excess is excreted. Liver is also rich in folic acid but should not be eaten during pregnancy because it also contains high levels of vitamin A which could harm the baby.