Network diagram Folic acid is a B vitamin, also known as vitamin B9, which is water-soluble. It was first extracted and purified from spinach leaves, so it was named folic acid. Folic acid is one of the essential substances for the growth and division of human cells, is an essential factor for the synthesis of protein and nucleic acid, is closely related to the metabolism of the body, and is an indispensable nutrient in the process of embryonic development. But the human body cannot synthesize folic acid itself, and needs exogenous folic acid to supplement the body needs. Therefore, it is generally emphasized to supplement folic acid in time during pregnancy preparation.
Folic acid contributes to the healthy growth of the fetus. Taking folic acid in preparation for pregnancy can prevent birth defects such as fetal neural tube defects (NTDs), fetal congenital heart disease, cleft lip and palate and other body surface abnormalities, and can also prevent anemia in pregnant women and fetuses, promote the development of fetal nervous system, reduce pregnancy response, and reduce the risk of preeclampsia in pregnant women.
Many women of childbearing age begin to take folic acid after they know they are pregnant. At this time, eating folic acid has not played a great role in preventing NTDs. Because under normal circumstances, the neural tube of human embryo is closed 21 to 28 days after pregnancy. If the maternal folic acid level is insufficient during this period, the neural tube of the fetus may be blocked, leading to NTDs. Studies have shown that women of childbearing age who take 0.4 mg of folic acid every day will improve their folic acid deficiency after 4 weeks; After 12 to 14 weeks of continuous supplementation, the serum or plasma folate concentration reached an effective level and remained stable. Therefore, the best time to supplement folic acid is three months before pregnancy. It is recommended to supplement 0.4 mg or 0.8 mg daily until the third month of pregnancy. In view of the other benefits of folic acid to pregnant women and fetuses, there are also experts in China who suggest that the whole pregnancy should be covered.
Some people will think that "medicine has three kinds of poison", and they want to supplement folic acid through diet, which is far from enough. Although dark green vegetables, citrus fruits, beans, nuts, animal livers and other foods are rich in natural folic acid, the bioavailability of natural folic acid is low, only about 60% of synthetic folic acid. Therefore, the effect of folic acid supplements will be better for pregnant women and pregnant women. At present, there are two kinds of folic acid tablets with single component in China, namely 5 mg/tablet and 0.4 mg/tablet. Common folic acid tablets (5 mg/tablet) are used to treat anemia and other diseases. Folic acid supplements (0.4 mg/tablet) are preventive drugs, which can be selected by pregnant women. Folic acid supplements are over-the-counter drugs. You can buy them at regular pharmacies or hospitals by yourself. When you buy them, look for the drugs produced by regular pharmacies. Don't be superstitious about expensive drugs.
It should be noted that the more folic acid you take, the better. Taking folic acid in large doses for a long time will lead to a significant increase in the blood concentration of folic acid in pregnant women, interfere with the metabolism of zinc, a trace element in the body, and cause zinc deficiency. Therefore, excessive supplementation of folic acid has certain potential risks, and pregnant women should take it correctly according to the doctor's advice.
Wu Yingqi, pharmacist in charge of Anhui Provincial Hospital, First Affiliated Hospital of China University of Science and Technology
