With increased estrogen, as in pregnancy or when taking birth control pills, folic acid supplementation helps prevent deficiency symptoms. More is also required during lactation, which it also aids. Folic acid is often used when there are any menstrual problems. The "restless leg syndrome," which is characterized by creeping, irritating sensations in the legs and occurs most commonly in later pregnancy, is often helped by increasing folic acid, as it may specifically be a deficiency problem.

With both folic acid deficiency anemia and pernicious anemia, folic acid is usually supplemented along with vitamin B12. The fatigue, easy bruising, and inflammation of the tongue that may go along with anemia are often helped as well. Treatment of various blood diseases, osteoporosis, and atherosclerosis has been supported with folic acid. There is some suggestion that it helps in ischemia, with reports of improved blood flow to the eyes and improved vision in those with circulatory deficits.

Folic acid has been used for chronic diarrhea or malabsorption problems and to stimulate a depressed appetite. It may also be helpful in some cases of depression, dementia and brain disorders, epilepsy, or neuropathies, especially when deficient. Folic acid supports healthy skin and may help in healing skin ulcers, particularly of the leg, or sebborheic dermatitis. Usually 1 mg. tablet daily or an oral folate solution may be helpful in treating gingivitis or other periodontal diseases. It has been suggested and used with varying results, usually along with PABA and pantothenic acid, to prevent the graying of hair. Higher doses may have some use in healing dysplasia (precancerous cell changes) of the cervix, which is often associated with lowered folate levels. Further research is needed to substantiate some of these uses.

Deficiency and toxicity: There are no specific toxic symptoms from folic acid intake, at least up to 5 mg. daily. However, excess folic acid in the face of a B12 deficiency, when B12 is not supplemented and absorbed, may lead to serious consequences. Folic acid will mask the B12-related anemia and early symptoms of vitamin B12 deficiency by helping the synthesis of DNA and red blood cell production, but folic acid has no effect on the myelin sheath covering the nerves, so nerve damage may occur where folic acid covers up a B12 deficiency. Higher doses of folate may also depress B12 levels. In recent research where higher levels (15 mg. daily) of folate have been used, some side effects developed after a month of treatment. These included gastrointestinal symptoms, insomnia, irritability, and malaise.

Folic acid deficiency is fairly common. It generates a picture similar to that of a B12 deficiency—anemia, fatigue, irritability, anorexia, weight loss, headache, sore and inflamed tongue, diarrhea, heart palpitations, forgetfulness, hostility, and a feeling of paranoia. Often, the mental symptoms occur before the anemia, with poor memory (possibly from decreased RNA synthesis), general apathy, withdrawal, irritability, and a decrease in basic mental powers.

Folic acid-deficiency anemia is not correctable with iron, and as it progresses, it will appear very different from iron-deficiency anemia. The blood will show large, irregular red blood cells, while low iron causes small red blood cells. In pregnancy, this megaloblastic anemia is of great concern. Folic acid deficiency is very common during pregnancy, when the requirements are at least double those for the nonpregnant state. Since folic acid stores in the liver can last several months, deficiency symptoms are more likely in later pregnancy. The fetus can readily draw on the folic acid of the mother, and deficiencies can cause problems in both. The mother’s folacin-deficiency mental symptoms of indifference, lack of motivation, withdrawal, or depression may be passed over as hormonal. The anemia may likewise not be considerd a matter for concern. Serious problems can result from a major deficiency. Toxemia of pregnancy, premature birth, and hemorrhage are all possible in addition to the anemia of the mother. The fetus could develop birth deformities, brain damage, or show poor growth as a child. It is very important to supplement folic acid during pregnancy.