Aww, mama, I know yan ang confusing part ng pag-aaral ng dosage! Please check with your pediatrician first, sila ang makakapag-advise ng exact amount para sa size at health ng baby mo, kasi bawat bata talaga ay iba. That said, since ang packaging mo says 0.5, 0.75ml para sa 7 months to less than 12 months, and your baby is 9 months, you're within that range. A few of us mums usually start sa lower end (0.5ml) first to see kung paano ang baby, tapos alam mo na kung kailangan pa. But really, best mo talaga i-confirm with your doc para sa peace of mind!