Folic acid is a compound drug preparation for the prevention of fetal neural tube malformations. Pregnant women who want to vomit after taking folic acid may be caused by drug stimulation of the stomach and intestines or early pregnancy reaction. Common causes 1, drug stimulates the stomach and intestines: some pregnant women with sensitive stomach and intestines take folic acid, the drug stimulates the gastrointestinal mucosa and can lead to vomiting; 2, early pregnancy reaction: after women get pregnant, the level of estrogen and progesterone in the body will rise rapidly, which triggers a series of early pregnancy reactions in pregnant women, such as nausea, vomiting, loss of appetite, dizziness and weakness. Therefore, vomiting after taking folic acid may not be directly related to the drug itself, but due to the early pregnancy reaction. For pregnant women with mild symptoms, it is recommended to continue to take folic acid and change the time of taking folic acid to half an hour after meals, so as to reduce the irritation to the gastrointestinal mucosa. For pregnant women with more serious symptoms, they can follow medical advice to reduce the dose appropriately and eat more folic acid-rich green vegetables instead of folic acid preparations, such as broccoli and lettuce, which can also play a role in preventing fetal neural tube malformation. Pregnant women will have obvious early pregnancy reactions in the early stage, but the degree of early pregnancy reactions varies according to individual physique, and some pregnant women with strong early pregnancy reactions may even be unable to eat, so they can take vitamin B6 as prescribed by the doctor to reduce early pregnancy reactions or go to the hospital for treatment.