@MikeMason-- I know what you mean. There is just a lot of information out there, at times supportive of each other and other times contradictory.
I don't want to confuse you more, but I have had improvement in my condition after I added niacin (vitamin B3) supplements to my diet.
Whether vitamins will work for erectile dysfunction or not mainly depends on what that person is in need of. If you have a deficiency in a vitamin, treating that will certainly help erectile dysfunction.
You might want to ask your doctor to do some blood tests for you to see if you have any deficiencies right now. If you do, you can start supplementing those first and then go from there.