I don't see why you would need to give calcium pills- as long as baby is drinking enough milk.
I could see why you might need to give them to a toddler or child, if you couldn't get them to drink much milk but most toddlers I know love milk, includ. my son, so not a problem.
Diet can always be supplemented with calcium rich foods, includ. cheese, yoghurt, leafy green vegetables and sesame.
It's obviously very imp. for babies and toddlers to have enough calcium (growing bones) but that's why they drink milk!