We recently done the blood tests of my son  who is 3.5 years old and although all reports are normal his b12 results are extremely high its 1476. We checked with doctor but he was not concerned of this at all. We are observing he is having burping issues and passing gas regularly..even in his sleep he wakes up with coughing and it seems he wants to burp but not able to do it. He complains he is full after eating very less amount of food. What we can do in this case?.