Good morning po! Ah yan talaga, nangyari din sa baby ko yan with iron supplements, nakakahiya ang tooth staining talaga. Siguro best to check with the dentist or pedia kung may alternative iron brand na less prone to staining, o pwede ring i-adjust kung paano ibibigay (like with straw, rinse agad after). One of my mum friends swears na pag nilagyan nila ng water ng vitamin, mas nag-lighten yung stain kaya try mo rin baka makatulong, pero really importante pa rin makita ng doctor para sigurado na getting enough iron pa rin ang baby while managing the staining issue.