I think with children it's more important to have them eating more healthy foods so that constitutes their needed vitamins and minerals. Taking them outside and having them be active helps too.

I know that could be a little more difficult depending on where you live but having them eating the right vegetables, meats, fruits, and grains goes a long way with avoiding sickness. Avoiding sugary stuff is another good idea - NO SODA OR SUGARY DRINKS - have them drinking water most of the time (your one year old should be getting plenty of milk still, probably around 8 oz per day at least.)

I also think you really need to be extra careful about administering vitamins to children because I think it could wind up causing them more harm than good. Giving too much can tax their system, probably mainly the kidneys, and that could wind up giving them stones...

So... I think overall it's up to you what you'd want to do, nobody's going to give you SOLID advice because it's not something people typically wants to screw around with - what I can tell you though, definitely don't go overloading them with too much of any vitamins or minerals. Maybe you can do some math and figure out what these vitamin protocols are based from - what the average weight of a person might be for taking the regimen - adjust proportions according to your children's weight and go a little lower on the doses....