Folic acid, also called vitamin B9, is a water-soluble vitamin. Sino-US cooperation project on preventing neural tube defects was launched on 1990. Through the follow-up observation [1] of 250,000 newly-married women and their pregnancy outcomes by Chinese and American scientists, it is verified that the preventive rate of expectant mothers taking 0.4 mg folic acid during pregnancy preparation is 85% in areas with high incidence of neural tube defects and 4 1% in areas with low incidence of neural tube defects. This scientific and technological achievement has been recognized by more than 50 countries around the world. Folic acid is also used to treat female anemia, but consumers must read the instructions carefully when choosing to buy and make choices according to different situations.