Is there anything you try to do to boost your LO's immune system? Or ways that you try and prevent them from getting sick?

I never worry about it much in the summer, but once school hits I make sure LO sanitizes her hands in the car after school. That's about all I do...I just cross my fingers she doesn't get sick too much this year!

ETA: We used to do daily vitamins but I've been forgetting lately.