No....I'm not a vegan but I try and stay away from most animal products so fish oil is a no-no.
I do take some supplements but not on a day-to-day basis. Echinacea is great during cold/flu season as it builds up your immune system but you can't take it for too long or you'll become intolerant. If you start feeling the early symptoms of a cold, Echinacea can sometimes prevent it completely, if taken early enough, and if not taken early enough, it can reduce a 7-8 day cold to 3-4 days.
Garlic and Ginger based supplements are great too.