Cod liver oil or any fish oil is used to try to balance the omega 3's & 6's. We typically eat too much omega 6's, so we take fish oil to keep those numbers at a healthy level. Cod liver oil, imho, can be really good, but you cannot take too much because it is usually fused with vitamin e to keep the oil from oxidizing and too much vitamin can be bad. But, i think its good stuff. Iv'e been taking it and i like it, i just limit it to one serving a day. Cod liver oil and fish oil are very similar (and are used for the same purposes), i weighed my options and i thought, for my situation, that cod liver oil is the best.