The differences between cod liver oil and vitamin AD are as follows: First of all, the ingredients of cod liver oil and vitamin AD are different, cod liver oil is a nutrient extracted from the liver in deep-sea fish. And vitamin AD is a combination of vitamin A and vitamin D micronutrients. Secondly, vitamin AD does not include cod liver oil ingredients, while the ingredients of cod liver oil include vitamin AD. vitamin AD only contains vitamin A and vitamin D, while cod liver oil contains many fish nutrients in addition to vitamin A and vitamin D. In addition, cod liver oil is mainly naturally ingested and the ratio of cod liver oil fluctuates, while vitamin AD is synthetic and its ratio is usually synthesized according to a 3:1 composition. In conclusion, cod liver oil and vitamin AD are somewhat different, but have the effect of providing the body with vitamin A and vitamin D.