hypercalcemia with low associated PTH- follow up.

I wrote a month ago about an incidental finding of hypercalcemia (11.4) during a check up, with low-normal PTH. CT of chest/abdomen with normal results. Since then serum calcium returned to normal range (10.6). Have been under the care of an endo. Initial tests revealed normal 24 urine calcium, low-normal phosphorus, vitamin D deficiency. On vitamin D treatment for a little over a month, and new test results reveal: normal calcium (10.6 again) PTH of 15 (originally 12), phosphorus has risen to mid-normal, but bone density scan (taken early on in the Vitamin D treatment) reports osteopenia in spine (-2.3). Endo. will be putting me on phosphorus meds and I will continue vitamin D. But isn't osteopenia a little odd for a 32 year old male? My Endo. seems unworried, as long as treatment is successful. Could the osteopenia-phosphorus-vitamin D relationship have been causing hypercalcemia? I have admittedly lacked in dietary intake of calcium and vitamin D since @ age 4 (refused to drink milk, still eat very little dairy). I may have also lost some height (less than an inch) in the last few years. Could this all be a manifestation of a more serious bone-related disease? Is primary hyperpara. completely out of the question because of PTH? Anything else I should be doing?

Thank you.

[Mark Lupo, M.D.]

Make sure both 25 and 1,25 Vit D forms were checked.

PTH would be usually elevated in vit D deficiency and the history does not seem to be primary HPTH

Would consider osteomalacia as a possibility.

Go by Z scores and not T scores (ie which was the -2.3) in male

You may have never fully formed bone given low diet intake of ca/vit d

Make sure sprue is tested for and testosterone is looked at as well as thyroid function.

Good luck.