Low back pain

my 15 yr old son was having lower back pain.  we went and had an MRI done.  The MRI states:
1. Stress response involving the right pedicle and pars interarticularis and to a much lesser degree the left pars interarticularis of L4
2. Subtle bulges L3-L4 and L4-L5

My son wrestled his Freshman high school year and would like to wrestle his Soph.  The dr. told us that he has Schmorl's nodes and a "pre-stress" fracture.

a. What would be reasonable treatment for him?
b. Can you heal a pre-stress fracture?  
c. Is there any vitamin suppliments I should look into him taking?
d. Should we allow him to wrestle?  There is 6 months before next season starts.
e. any excercises best suited?
f. can schmorl's nodes be completely healed?

I have started him in PT.  I plan on doing Yoga/Pilates with him to help him with his core.  

[meg8]

i have been diagnosed with  schmorl nodes about 5 years ago they told me that only threpy can help but can never heal i can still play sports and it wont stop you from play any sports i was 12 when i was told i have it and now im 16 and still playing sports with schmorl nodes it really dosent bother me that much anymore but im pretty sure he can still do wrestle with wrestle