Please ask your physician if he enjoys being badgered about every possible question, instead of letting him do his job and suggest to you the best care.
It's part of the conduct of a "professional" to act responsibly. I don't know of any true profession that doesn't have some aspect of that as part of its foundation. Structural engineers are expected to point out buildings that are about to fall; a pharmacist is expected to point out possible dangerous interactions; a geologist is expected to notify residents if a nearby volcano is about to erupt; etc. A patient should be able to be confident that his physician will suggest the appropriate care, not require him to guess the right question to ask!
And physicians are there in part to answer your questions about your healthcare, not to read your mind. If they are not telling you to take fish oil they probably have a good reason in their mind but you know what? They might not tell you unless you ask.
In my experience physicians are more than happy to answer questions, especially good ones. Seems to me they are "doing their job and suggesting to you the best care" and yet you bitch that they don't tell you about fish oil? and then you say you shouldn't ask questions because they don't like being badgered?