I have no problem when a doctor suggests Vitamin D supplementation for a baby or child, as that can easily be done (if needed) without interfering with breastfeeding in the least. What I have a problem with is the suggestion a mothers milk is inferior to another mammals milk and must be replaced BY that other mammals milk because it is not fortified. I find it an undermining way of putting it that suggests breastmilk is some how deficient, nutritionally. When it is NOT.
I suspect this was the doctors way of explaining something kind of complicated in the time she had. Nevertheless, words matter. A mom who was less savvy about breastfeeding or less confident in her ability to nourish her child than stonesmom may be undermined by such words.
My very breastfeeding friendly Ped also has outdated, undermining nonsense printed on the "at this age baby should...." themed hand outs. It's a multy ped office and I suspect he has no control over it.