I usually have a morning smoothie (or use it as a mid-morning snack) that I put some type of meal replacement vitamin-mineral-protein powder in ( usually "Vegan Complete") as well as ground flax, or a flax/glucosamine joint powder. On days that I don't do this, I will take a multivitamin. I also take a spritz of sublingual B12 spray a couple of times a week.
If you are considering adding supplements to your diet, take into account other sources of vitamins/minerals you may be consuming, such as cereals, drink mixes, etc. You don't want to get too much vitamin A (especially if it's not betacarotene), vitamin D or iron.