Hi, I give Formula milk (Aptamil Gold stage 1) to my baby who is 3.5 months old . His weight is 6.5 kg, his birth weight was 2.8 kg. Dr said he has gained very good weight. so Dr asked me to stop Aptamil and start Similac the another formula brand. Dr said Aptamil has high ingredients which is not needed by baby . so he said to switch to Similac. my question is Is it Okay to switch from Aptamil to Similac, Is there any side affect?????