Supplementation of calcium, iron and folic acid for pregnant women in their 4th month of pregnancy. 1. Calcium: The rapid growth and development of the fetus in mid-pregnancy is a critical period for bone development, and the demand for calcium increases, so attention should be paid to supplementing calcium, which can be supplemented through food, such as dairy products, soybean products, seafood or milk powder for pregnant women, and if the lack of calcium is more serious, calcium tablets can be taken under the guidance of a doctor to supplement calcium. 2. Iron: to prevent iron deficiency anemia, you can eat appropriate, such as animal liver, beef, lean meat, etc. If the anemia is serious, you can take oral ferrous sulfate and other drugs under the guidance of a doctor. 3. Folic acid: throughout pregnancy, the synthesis of fetal DNA in all cells requires a large amount of folic acid, so we should pay attention to folic acid supplementation, but folic acid in food can not meet the needs of the fetus, you can eat multivitamins containing folic acid. It is recommended that pregnant women in their 4th month of pregnancy undergo regular obstetric examinations and consult the relevant doctor if you have any questions.