Just to establish... from what I've read, excess Vitamin A can be harmful, so if you're going to supplement, especially if you're not monitoring the level of vitamins in everything you eat, it might be safer to supplement Beta Carotene. Beta Carotene is converted by the body into Vitamin A, but only at the necessary needed levels.
If this is so, I suppose I have to wonder, why do they put vitamin A into multi-vitamins and other things like cereals at all, when beta-carotene is so much safer? Instead of messing you up like excess vitamin A, any excess beta carotene just goes to turn the skin orange or something, which I think is a perfect indicator. I wish all vitamins did something obvious when there was excess just so you knew you were getting enough, because recommended daily allotments are so inaccurate.