baby breast feeding wear for bridesmaid

A wise mama asks:

I have a question about breastfed babies being vitamin D deficient. My pediatrician told me my son would need vitamin d drops because he is breastfed . I purchased the enfamil drops, well he soon became so gassy and just fussy. I could tell they were hurting his little tummy. I was just wondering what some thoughts were on vitamin D drops? baby breast feeding wear for bridesmaid