And why (if you want to answer)? Are you trying to prevent certain diseases? Or, are you using them as an alternative to conventional medication for a current condition?
I take magnesium, vitamin b12 (100 mcg), and l-lysine.
I take magnesium whenever I'm feeling super anxious and wired. It really helps me fall asleep when I can't. It is like a natural sleeping pill.
This isn't really considered as a supplement, but I try to drink at least a cup of green tea a day. I've heard that it could help to prevent cancer. I don't think one cup is enough, but it won't hurt. I've also heard that it can help fight bugs. I drink an extra cup if I've been around someone sick or eaten something from a sketchy restaurant.