Cod liver oil contains vitamin A and vitamin D. It is an important vitamin supplement. Cod liver oil is suitable for teenagers, infants and young children. The best time to consume cod liver oil is 30 minutes to 1 hour after feeding or eating. Cod liver oil is important for people in growth and development as it strengthens the body, promotes calcium absorption and improves vision development. Infants and young children start taking it from 3-4 cycles after birth, and depending on their digestive ability, they can consume Cod Liver Oil Drops, one drop per day, up to a maximum of five drops. Teenagers can swallow it directly to promote calcium absorption, normal growth and development, and prevent vision loss and rickets. Cod liver oil supplementation with vitamin A and vitamin D can only prevent rickets, but when the body is in the stage of calcium deficiency, taking cod liver oil can no longer correct the calcium deficiency, the patient should go to the hospital nutrition department. At the same time eating cod liver oil should be based on the age of moderate consumption, so as not to cause vitamin A poisoning.