Salmon and fish oil pills good? better to take cod liver oil alone? is cod with vitamin a safe?heard "a " stays in body,so what if you have too much?

They're OK, but...: No food or vitamin is particularly healthy by itself. Eat a balanced diet with lots of plants and not too much red meat. Beyond that, maybe a multivitamin, but there's no proved health benefit from extra amounts of any vitamin or nutrient. And yes, carotenoids (vitamin A and related compounds) can accumulate in the body, turning skin and eyes yellow-orange. ("Carotenoid" comes from "carrot".)