It is a rich source of Omega 3 fatty acids (although other fish oils may have more), and studies have shown that these are helpful in treating arthritis. Cod liver Oil is also rich in Vitamins A and D. It has also been widely used for arthritis pain for generations. In fact a UK study of home remedies found it to be one of the most common. Although eschewed in the past, it now is usually found to be true that remedies that are in longstanding popular use do have value. Ultimately you can only tell by trying it if you are so inclined – and it may well be that there is another nutrient that we are not aware of that is partially responsible for its beneficial effects. It is clear however that a fish oil supplement and a Vitamin D supplement are useful for virtually everyone, and this regimen probably provides what the Cod Liver Oil does. But if you want to give it a try, it certainly will not be harmful, and you can gauge the results for yourself.