I have given lactogen stage 1 to my 1 and half year old baby (90ml with 3 scoops). But he is vomitting it now. Same happened when I gave nan pro 1. preparation method was hygiene and ratio was also correct as mentioned in the box. but why he's vomitting? somebody pls give me solution. I'm confused and worried

Why stage one for a one and a half year old ? You can also start with cows milk after discussing with your doctor If your child throws up cows milk too and repeatedly then it may be a reaction to lactose and you need to avoid the same. Also keep watch if the same reaction happens with other foods as well.