Multivitamins are best taken all the time during pregnancy. Vitamins are necessary for regulating body metabolism and maintaining a variety of physiological functions, and are also essential nutrients for fetal growth and development. Insufficient or excessive supply of vitamins in early pregnancy can increase the risk of fetal malformations, and the amount of vitamins needed in mid- and late pregnancy should increase due to rapid fetal growth. Poor nutrition during pregnancy not only leads to miscarriage, premature birth, fetal malformation, etc., but also possible pregnancy complications, such as pre-eclampsia and diabetes, etc. The intake of vitamins needs to be increased throughout pregnancy, and it is recommended that when pregnant women take oral multivitamins, they should be applied under the guidance of a physician.