Why is this even controversial? Fetuses, babies, and children need certain nutrients to grow healthy. Vitamin A, Zinc, Iron, Folic Acid, etc.. Iodine has to do

Why is this even controversial? Fetuses, babies, and children need certain nutrients to grow healthy. Vitamin A, Zinc, Iron, Folic Acid, etc.. Iodine has to do with good brain development, vit A with eyes (among other things), etc. What's the problem? It's elitist and western to think that people should have a chance to grow up healthy? And to think that this will lead to better outcomes on average?