Original sentence: " Depending on the quality of the oil the flavor and aroma range from a mild sardine flavor, to an intense and obnoxious odor of rotten fish and rancid oil.Cod liver oil and fish oil are similar but have a somewhat different compostion: fish oil has a much lower contenct of vitamins A and D compared to liver oils.Cod liver oil is a significant source of supplemental vitamin A and Vitamin D, it is also an excellent source of omega-3 fatty acids (EPA and DHA).Cod liver oil is made by cooking cod livers with steam and then pressing/decanting the cooked livers to extract the oil.Fish oils are extracted from the whole body tissues of fatty fish during the manufacture of fish meal.High quality cod liver oil is  "a pale-yellow, thin, oily liquid, having a peculiar, slightly fishy, but not rancid odor, and a bland, slightly fishy taste.Prior to the fortification of milk with vitamins A and D, it was commonly given to children as a nutritional supplement.Shark Liver Oil
Edited sentence: Americans consume an unbalanced amount of omega-3 and omega-6 fatty acids.Cod liver oil and fish oil are similar, but not the same.Cod liver oil is a significant source of supplemental vitamin A and D.Cod liver oil is also a good source of EPA and DHA, however, unlike fish oil, it contains vitamins A and D.Currently the ratio between these fatty acids is somewhere between 1:20 and 1:50, but the ideal ratio is 1:1.Fish oils are extracted from the tissues of fatty fish like salmon and herring and are good sources of omega-3 fatty acids EPA and DHA.For example, scientists in the United Kingdom are pushing for cod liver oil supplementation in schools  and Kellogg signed a 15-year agreement with Martek Biosciences to provide omega-3 fatty acids for its breakfast cereals and cookie products.Once commonly given to children daily as a nutritional supplement, it is rarely given today, but is gaining popularity.Scientists are discovering that it isn't just the vitamins in cod liver oil that are healthy, but the omega-3 fatty acids found in fish oils also help fight and prevent various ailments.The lack of omega-3 fatty acids is making it popular to daily supplement one's diet with high quality fish or cod liver oils