not sure if it is necessary but I give. I bought mine from iherb. you can look through the web to see what they have and also the ingredients of the supplements and see what you are comfortable with. I give Nordic naturals DNA, BioGaia, VitD and multivitamins.
I do only because we don't always have a consistent healthy diets of veggies etc everyday. So I use it as a supplement.
immunped / immunorm. I also give nordic naturals dha, honey and kids3 HDI
sambuccol