Has he had his bloodwork done more than once? Some (not all) of the values can change from day to day. I'm not sure about calcium; I know glucose can & some others.
High calcium & weight loss may indicate cancer, though you dog is young....I would definitely ask your vet about it though. Perhaps he can refer you to an oncologist, or whatever specialist he feels might help you figure out what's going on...?
Good luck with him, let us know how he's doing!
PS, don't mean to alarm you about the cancer thing. I'm not a vet professional; for all I know it could be something much less serious. But I remember the blood calcium thing from when my last old Rottweiler got bone cancer.
Cooper The WonderDog
Daphne The Destructo-Rott