The studies that seem to indicate that Vitamin A is toxic where not done with BOTH Vitamin A AND Vitamin D. The Ratio of Vitamin A to D is 10:1. This has a protective effect.
The other issue is impurities. This is a false premise. All cod liver oil sold is tested for impurities. Lead, other heavy metals, etc. It has to pass muster before coming to market.
Here is a link to the article that explains the toxicity issue:Vitamin A on trial
The benefits of cod liver oil are so strong that I think there should be an entire forum at curezone devoted to it.
Start taking it, and see for yourself. The studies for the benefits of DHA and EPA in fish oil are growing. Doctors are now prescribing fish oil to their heart patients.