L.W.
That may just be how his biological clock works. My cousin, from the time he was born until now (he is 39) wakes up at 5:30 in the morning. He used to play quietly in his crib or room but that is just how he is. His daughter is the same way.
My son is an early riser as well. It doesn't matter what time he falls asleep he is awake by 7:15 at the very latest every day. He's been like that since he was a newborn.
And to the person who talked about additives...I'm certainly all for a healthy diet but both my cousin and my son are on hugely healthy, largely preservative free diets. I cook nearly everything from scratch as did my Aunt (my Uncle opened and operated one of the very firts health food stores in Chicago 35+ years ago.
For us...it's just the way we are made. Everyone has different sleep needs and a different internal clock. If he is not tired all day and acting out I would just learn to accept it. Personally, I think it's great that he's up to get a jump start on his day and I know it will serve him well when he's older.