Owen and his dayhome eating habits

Ok so I am sure every parent experiences the "Oh I hope my child was not the weird one at daycare today". I get that feeling everyday at 5:30 when I pick up Owen from Hethr's. If you don't know Owen well...he is on the road to becoming quite the little OCD child. If you come in from outside and snow falls off your boot...it goes in the garbage, if he finds the smallest lint...it goes in the garbage, doors need to be closed, he puts handlotion on his hands everyday with Nanna and insists you smell it. That is not the weird part....this is just some of the few things that Heather has informed me my child has eaten: potting soil
sand
sucked a marker dry

and my new personal favourite...He decided to eat her support beam in the basement. She has his little teeth marks on the beam.
So my dietitan friends out there in internet land...what on earth is my child missing in his diet that requires him to eat these weird objects?

I absolutely adore the fact that Owen is coming into his own personality so well but why on earth does he have to be so bizarre? :)