There is no uniform conclusion as to whether DHA is necessary. Generally speaking, if the daily diet is rich in food variety and reasonably matched, then DHA is best supplemented by food, and if dietary supplementation is not sufficient, it can be supplemented by supplements. DHA is a polyunsaturated fatty acid, one of the essential fatty acids, which can maintain the normal function of the optic nerve and the brain, and also promote fetal brain development. DHA has a wide range of food sources, and common seaweeds are rich in DHA. When marine fish consume seaweeds, DHA is easily enriched in the fish meat. So as long as you eat seafood twice a week, DHA can basically meet your needs. However, if you are unable to supplement DHA through food due to factors such as picky eating, allergies, or inconvenience in obtaining it, you can purchase DHA supplements to supplement it. Although DHA is a beneficial fatty acid, it is not recommended to consume it in excess, as there are health risks associated with overdose. Consult your doctor if necessary.