At present, there are two aspects of nutrition for pregnant women and lactating mothers in China that deserve special attention: 1. Micronutrient deficiencies such as iron, calcium, zinc, vitamin A, vitamin B2, and folic acid are more common, and the intake of many micronutrients is significantly less than their actual needs, thus seriously affecting the health of pregnant women or lactating mothers and the growth and development of their offspring before and after birth. 2. Excessive energy intake of pregnant women and lactating mothers is more common in cities. The above two situations lead to nutritional imbalance of pregnant women and lactating mothers. A balanced diet is the key to the diet of pregnant women and lactating mothers: During pregnancy, many tissues and organs of the mother’s body undergo a series of adaptive changes and the metabolism of the body increases, while the growth and development of the embryo and fetus also require a large amount of nutrients. Therefore, nutrient deficiencies or inadequacies during pregnancy can have serious effects on both the mother and the fetus, and nutritional status during pregnancy may have a significant impact on the long-term health of the offspring in adulthood. Nutrition during lactation involves both the feeding of the infant and the recovery of the mother herself. On the one hand, lactating women produce milk and nurse their babies, and on the other hand, they have to restore the functions of various organs and systems and compensate for the nutrient reserves depleted during pregnancy and childbirth. Therefore, lactating women also have a comprehensive need for various nutrients. The nutritional needs of the human body and the distribution characteristics of food nutrients determine that a balanced diet must consist of a variety of foods and the appropriate proportion of each type of food. Folic acid is an important methyl donor in the body and can affect the expression of many gene functions. Folic acid can re-methylation of methionine metabolite homocysteine to methionine, thus reducing the toxic effects of homocysteine, while high concentration of homocysteine in the body can increase the risk of adult heart, cerebrovascular disease and tumor, and is also a risk factor for pregnancy complications such as gestational hypertension and preeclampsia. It is also a risk factor for pregnancy complications such as gestational hypertension and preeclampsia. Chinese women of childbearing age who are not given dietary supplements have an average folic acid deficiency rate of 30%. Folic acid is found in natural foods in the form of folic acid salts, which must be converted to folate in the body before it can be used by the body. Women of childbearing age should consume folic acid-rich foods as early and as much as possible when planning a pregnancy. Since folic acid supplements are better absorbed and utilized by the body than folic acid in food, it is recommended that folic acid supplements of 400ug per day should be taken from at least 3 months before pregnancy and continue throughout pregnancy. The importance of iron supplementation for pregnant women and lactating mothers: Studies have found that iron deficiency anemia and iron deficiency are still high among pregnant women and lactating mothers in China, and that perinatal iron deficiency not only damages the health of pregnant women themselves, but also reduces iron reserves in the fetus, making it a major cause of iron deficiency anemia and iron deficiency in newborns and infants. Dietary sources of iron are divided into animal and plant foods, with high iron absorption and utilization in animal foods and poor iron absorption and utilization in plant foods. Tea and coffee can interfere with iron absorption, while vitamin C, citric acid, lactic acid, etc. can promote iron absorption. Foods rich in iron and high absorption rate are mainly animal blood, lean meat and seafood; liver foods are rich in iron and have high iron utilization rate, but liver foods have high vitamin A content and should not be consumed in excess. You can eat more foods that promote iron absorption, such as citrus fruits rich in vitamin C and citric acid, and sour dairy products containing lactic acid. Currently, it is recommended that perinatal women consume the following amounts of animal foods daily and choose iron-rich varieties as much as possible to basically meet their iron needs In the first trimester, 50-75g of animal meat, 50-100g of fish and shrimp, 25-50g of eggs; in the early trimester, 150-200g of fish, poultry and eggs (at least 50g each of fish, poultry and eggs); in the middle and end of trimester, 200-250g of fish, poultry and eggs (at least 50g each of fish, poultry and eggs); in the lactation period, 200-300g of fish, poultry and eggs (at least 50g each of fish, poultry and eggs); in the lactation period, 200-300g of fish, poultry and eggs (at least 50g each of fish, poultry and eggs). At least 50g of fish, poultry, eggs). Fourth, the role of calcium: calcium nutrition deficiency is a more prominent problem of women during pregnancy and lactation. The full-term fetus contains about 25-30g of calcium, all from the maternal supply, mainly accumulated in the middle and late pregnancy. Ideally, the mother also has to reserve some calcium during pregnancy for use during lactation. When calcium intake is insufficient, the mother needs to mobilize calcium stores in her body’s bones, reducing her bone calcium material and increasing her risk of developing chondromalacia and osteoporosis. Adequate calcium nutrition during pregnancy may reduce the risk of maternal hypertensive disorders of pregnancy and preeclampsia. Dairy products are an ideal source of calcium, and the absorption of calcium from dairy products is not easily interfered with by other factors. Pregnant women and lactating mothers should consume more dairy products, and it is recommended that they drink at least 250 ml of milk daily, plus about 100 g of soy products and other calcium-rich foods. In addition to fresh milk, yogurt is also a good choice for dairy products. Vitamin D is an important factor in the absorption and metabolism of calcium, so calcium supplementation should be accompanied by vitamin D. Vitamin D can be supplemented by preparations, but the best way is to get more sunlight. V. Nutritional value of long-chain polyunsaturated fatty acids for pregnant women and lactating mothers: Fish foods are of great significance to pregnant and lactating women, and fish is the richest source of docosahexaenoic acid (DHA). Long-chain polyunsaturated fatty acids (DHA, arachidonic acid) have an important role in promoting intellectual and behavioral development in children. Therefore, pregnant women, lactating mothers and children are encouraged to consume appropriate amounts of fish, especially deep-sea fish. Fish oil supplementation for pregnant and lactating mothers may promote cognitive and behavioral development in children. However, fish consumption should also be in moderation. A U.S. study showed a dose-effect relationship between the number of fish consumed by women in the past 3 months and the amount of mercury in their hair, suggesting that fish consumption is an important pathway for mercury exposure. It is recommended that pregnant women and lactating mothers should not consume more than 340g of fish per week. Excessive energy intake is another common phenomenon among pregnant women and lactating mothers: Energy intake during pregnancy has always been a concern, but in the past, the concern was mostly about insufficient energy intake due to the improvement of living standards, while the current problem is more about excessive energy intake. Many families and pregnant women understand nutrition during pregnancy as the more nutrition the better, and while increasing the intake of iron, calcium, vitamins, etc., too much food is consumed, resulting in excess energy; coupled with the obvious reduction in daily work and activity during pregnancy, an imbalance between energy intake and consumption is more likely to occur, resulting in an increase in obesity and the birth rate of huge babies. Studies have shown that excessive weight gain during pregnancy and failure to lose weight after delivery are important factors leading to female obesity. Therefore, in addition to a reasonable diet, proper exercise and breastfeeding can help reduce weight in lactating women.