In the fourth month of pregnancy, you generally need to supplement calcium, iron, folic acid, vitamin C, etc., as follows: 1. Calcium: the rapid growth and development of the fetus in the middle of pregnancy is a critical period for bone development, the demand for calcium increases, attention should be paid to supplementing calcium, which can be supplemented by food, such as dairy products, soy products, seafood or milk powder for pregnant women, if the calcium deficiency is serious, calcium tablets can be taken under the guidance of a doctor to supplement calcium; 2. 3, folic acid: throughout pregnancy, the synthesis of all cellular DNA of the fetus requires a large amount of folic acid, so pay attention to the supplementation of folic acid, but the folic acid in food can not meet the needs of the fetus, so you can eat a multivitamin containing folic acid 4, vitamin C: to promote the absorption of iron, you can eat vitamin-rich fruits, such as oranges, grapefruit, oranges, etc.. In addition, in the fourth month of pregnancy, has entered the middle of pregnancy, the fetus in the uterus growth rate is faster, the demand for energy is increasing, at this time, pregnant women should pay attention to increase energy in the diet, food types should be diversified, meat and vegetables with comprehensive nutrition. In our daily life, we should eat more food with high protein and vitamin, such as milk, lean meat, shrimp, etc., as well as fresh fruits and vegetables to ensure the nutritional needs of fetal growth and development and promote the healthy growth of the fetus.