DHA, docosahexaenoic acid, commonly known as brain gold, is a very important unsaturated fatty acid for the human body, belongs to the Omega-3 unsaturated fatty acid family, DHA is a major component of cell growth and maintenance of the nervous system, is an important component of the brain and retina, in the human cerebral cortex content of up to 20%, in the retina of the eye accounted for the largest proportion, accounting for about 50%. Therefore, DHA is essential for the development of intelligence and vision in fetal infants. Three sources of DHA Deep-sea fish extract is extracted from fish fat and contains not only DHA but also EPA, which is particularly good for the cardiovascular system of the elderly. However, it depends on the ratio of EPA and DHA, if the DHA content is high, the corresponding EPA content is also high. The ratio of sea fish oil DHA:EPA is usually 4:1 or 5:1. For infants and children under 3 years old, high dose of EPA will inhibit the conversion of linoleic acid to AA, which will affect the absorption of AA and may affect the growth of young children. Moreover, DHA extracted from deep-sea fish oil is prone to contain PCBs (polychlorinated biphenyls), dioxins, heavy metals such as mercury, lead and many other heavy metals and irritants due to the deteriorating marine environment and the process of food chain transmission. The advantage of algae oil is that it is not passed through the food chain, does not interfere with the marine environment, does not contain pigments, is more easily absorbed, and has a strong antioxidant capacity that does not easily become fishy. However, algae oil needs to be extracted by extracting hexane (n)hexane, which is a derivative of crude oil and can be harmful to nerves if too high in the product. Algae oil DHA has become more popular in China in recent years, and many doctors recommend algae oil DHA. algae oil DHA is divided into T oil and S oil. t oil is the best quality algae DHA, directly from the marine single-cell dinoflagellate algae extract. It is supported by authoritative clinical trial reports (for infant brain and vision development), high DHA purity and content, basically EPA-free, so most of the infant products containing DHA are T oil. There are no clinical reports for infants and children. However, it is not recommended that pregnant mothers supplement algae oil DHA, now on the market in China, “algae oil DHA” belongs to the new raw materials from the product, by the relevant authoritative testing department, found that a product contains a very strong cholesterol and destroy the role of blood vessel lining cardamomic acid, lauric acid, the content of these harmful substances up to 22%, equivalent to half of its DHA content. At this stage, the developed countries of Europe, America and Japan, pregnant women and infants supplement DHA mainstream or from fish oil DHA, rather than algae DHA. Egg yolk extraction is a new technology in recent years. DHA is an organic combination of lecithin and DHA, and is also rich in lecithin, protein, vitamins and trace elements. Lecithin DHA is very easy to digest and absorb, no chemical residues, no heavy metal pollution, it is the safest DHA, very suitable for pregnant babies and children. For those who are allergic to eggs and egg products, a small amount should be tried before consumption. 0~3 months old infants are not recommended because their digestive system is not fully developed. When infants start to add complementary foods at 4 months of age, they can start with a small amount and gradually consume it in the same amount as the complementary foods. In fact, no matter algae oil, fish oil or egg yolk, which type of DHA products are not without drawbacks, so it is necessary to look at some products dialectically, and some new technology products also need long-term, a large number of clinical trials to prove the efficacy and side effects. DHA supplementation recommendations for each stage DHA is good, but certainly not the more the better. According to the U.S. Institute of Medicine (IOM) recommended daily intake of DHA for each population is 90-160 mg per day for ages 4-18, 160 mg per day for adults, and 200 mg per day for pregnant and lactating women. Specific to the different stages of pregnancy-6 years old are as follows: 6-9 months of pregnancy is the most important time for fetal brain development, and 70%-80% of brain differentiation has been completed before the fetus is born. The proper amount of DHA intake during pregnancy helps maintain the integrity of the fetal brain cell membranes and has the effect of promoting fetal brain development and improving memory. The remaining 20-30% of the baby’s brain differentiation at 0-6 months is completed during this period. A baby’s intake of the right amount of DHA can promote better hand-eye coordination, and this effect is most evident at the age of 2 years. Infants’ need for DHA comes primarily from the mother and breast milk. Scientists initially studied the nutritional composition of breast milk and found that Japan eats more fish and has the highest DHA content in maternal breast milk, with 22 mg in 100 ml of breast milk; the United States is 18 mg; Australia is in the middle. 6 months-2 years is the most rapid growth and development age of babies, DHA can produce a large amount of hormone that is vital to promote brain development to meet the baby’s development needs. 100 mg of DHA per day is a more appropriate amount, and if your doctor recommends that your child take a DHA remedy, then about 150 ml per week is safe. Children between the ages of 2 and 6 who have low levels of DHA in their bodies may be at increased risk for autism, vision problems and psychological problems. At this time the amount of DHA a child needs is about 200 mg per day, and if your doctor recommends that your child take a DHA remedy, then 250 to 300 ml per week is safe. Selection of DHA must pay attention to several points There are many DHA products on the market, and constantly pushing the new, in the face of this situation we first need to understand the following aspects: 1, look at the packaging logo General formal manufacturers of packaging will be clearly marked with the trademark, manufacturer’s name, production date, production batch number, net content, nutrient table, implementation standards, applicable objects, storage methods, and In addition, pay attention to whether the package is printed with the logo of the health food approved by the state, and whether it is printed with the GMP certification mark. 2, the manufacturer and brand Some mothers do not know what to choose when the product is good, may casually choose a good-looking packaging, and some mothers will choose a big brand, in fact, the latter direction is more correct. It is recommended that mothers ask more about the manufacturer of the product or the origin of the brand before purchase. Large companies with a long history of producing the product have stricter control over the production of raw materials, production processes, sub-assembly processes, quality tracking and effects, etc. The management is more experienced and the product quality is relatively more trustworthy. 3, price Due to the existence of domestic sources, raw material imports, the existence of the original imports, the price will exist a certain gap, in the purchase of their own actual situation to buy. 4, the source of raw materials In addition to these relatively easy to understand the external information, the purchase of DHA products is also recommended to investigate the product raw materials based on the source. If the production side choose to extract raw materials from polluted waters or poor quality ingredients, the product purity, safety aspects will be greatly reduced.