There are many benefits to taking folate during pregnancy, including a significantly reduced risk of birth defects. For most women, the pros of folate outweigh any concerns about the vitamin, which is generally considered essential to healthy conception and pregnancy. Folate intake may be troublesome for women with vitamin B-12 deficiency, however, and folate supplements have been linked to accelerated growth in pre-existing cancers, though this link is still unproven. As with any vitamin, folate may prove to be damaging in high doses or in rare cases of allergies. It is important that pregnant women always discuss any supplements or changes in diet with a medical professional.
Folate, or folic acid, is a water-soluble B vitamin that aids the body in synthesizing and repairing its DNA. Folate exists naturally in leafy green vegetables, and is considered so important to human growth and development that many countries require that it be added to packaged cereals and bread as an essential supplement. Folate deficiency in women who are pregnant or attempting to conceive is linked to an increased risk of fetal neural tube defects, including spina bifida and anencephaly. Women who do not have sufficiently high levels of folate during pregnancy may also increase their risk of preterm delivery, a baby born with congenital heart defects and low birth weight, and other problems.
Vegetarians, vegans, and other women with dietary restrictions should be aware that increased intake of folate during pregnancy may make it more challenging to detect the presence of a vitamin B12 deficiency, a highly rare disorder linked to pernicious anemia. Very high doses of folic acid may cause side effects including stomach cramps, nausea and diarrhea, sleeplessness, hyperactivity, and rash. Normal doses of prenatal vitamins do not contain enough folic acid to make this risk a serious concern for most women. Like all medications, there is a small likelihood that a woman may develop an allergy to folic acid. In this case, she should stop taking prenatal vitamins and seek medical attention.
Folic acid is linked to DNA replication in the body, and some studies have linked folate intake to accelerated growth in cancer cells. This connection is still uncertain, but pregnant women with cancer or women who are at high risk for certain cancers should consult with a medical professional before taking folate during pregnancy. In most cases, a physician will encourage the woman to continue taking a normal dose of folic acid, because of its known benefits to a healthy pregnancy and to child and maternal health.