I know when I started my character, I was getting 10 life per point of Vitality.
However, looking at my level 41 Barbarian, I see he's now getting 16 life per point of Vitality. As near as I can tell, this change isn't caused by any of my gear or skills.
What determines how much life you get per point of vitality? If it's level based, when does the number go up? Is it the same for all classes?