Calcium 2.29 mmol/l 25-hydroxyvitamin d 74 nmol/l pth 5.8pmol/l what do they mean collectively?

While all of these: calcium metabolism parameters are in the normal range, they are at the extremes of normal. You have a low serum calcium; we would expect the parathyroid hormone to be high(er) in this instance (which it is) trying to stimulate your bones to release calcium into the bloodstream to raise it. The 25-hydroxy vit D is ok (low normal). Not sure why these tests were obtained, but I see no big issues:)

High-norm vitamin D?: Most import, why did u have the tests, have you had neck surgery? Vit D & iPTH both raise Ca (Vit D raises Phos/iPTH lowers it).The ULN for vit D3 is 100 nmol/L,yours is Ok,but on the high end,prob GOOD!So iPTH does not have to be made to inc your Ca & goes down.You just need to have Phos check to make sure it's not high.CaPhos can cause kidney stones.A very low iPTH can also rarely cause bone dz✔️