I have a dad who is constantly sick. Every time I get him medicine and he gets better. Mom and the 4 kids have never been sick. I buy organic food, make sure they have plenty and give him fruit every time it is in the store. He's still always sick. I got a doctor consultation this last time and was told to give him throat drops. He's ALWAYS getting sick but the doctor never says anthing other than minor stuff is wrong. Any ideas>