Breastfeeding & vitamin D

I have one baby born 2019 and breastfed her until I had no more milk so about 6 months I stopped. I had another baby August 2020 and have since moved to a different state.

Took her today to a new pediatrician for her 4 month check and the doc asked If she was strictly breastfed and if I was giving vitamin D

I was so confused because my other pediatrician had never recommended it to me for my 1st 😲

Look into if and ask your pediatrician in case they have missed to give you this information , just wanted to post this since I'm 4 months into baby #2 and a new doctor told me.