Are all breastfeeding mummas giving their bubba vitamin D?

I'm trying to remember every day, we usually mix them into some expressed milk but can also just put drops onto back of her tongue like colostrum syringe too I think

You can put a drop on your nipple right before feeding and they will get it that way.

I was told to start at 4 weeks and either drops into mouth or onto nipple xx

I mix the drops into a bottle of expressed milk x

I will aim to give mine the drops but equally I only gave my first the drops about 3 times in total and he's turned out okay 😂