@Gingergrrl, have you had your genetics tested? My vit. D problem has a lot to do with my VDR gene. I have no idea about the calcium channel autoantibodies and sun sensitivity. My sun sensitivity is more heat related now, I think; maybe because of the VDR gene which can be supplemented and brought up in most cases.
I want to thank you very much for bringing up mentioning the N-type Calcium Channel Autoantibodies, though. I need to explore the channels and get some more testing done. I've known about them but don't know how they work, etc. and I didn't know about those autoantibodies. I'm way behind everyone on here.
A fairly "easy" way to suspect hyperparathyroidism is getting several tests several times. They should include serum calcium, parathyroid hormone (PTH), albumin and vit. D. Doctors seem to think without high calcium it is secondary calcium, but that's usually not the case. They also believe that your calcium will go up in a steady manner,, that's not the case. A parathyroid that has an adenoma (almost always benign) is out of control, so your calcium will usually be up, down, normal, etc.
It's the fluctuation of calcium that shows a problem. Also the higher the calcium the lower the pth should be. In normocalcemic, PHPT (pHPT?) even though the calcium is in the 9's, your PTH will usually be too high, even though it shows in the normal range. Kind of like TSH and thyroid levels.
Say one of my calcium levels was 9.9 (within levels of 8.8 and 10.4) and my PTH was 67 with levels of 15-76, that's a red flag. Several of these tests taken will almost always show calcium up and down and PTH different levels from middle to high. A lot of PTH is well over the limit. Some dr's believe as long as your PTH is normal range,also, that's ok because your ionized calcium is within levels. My ionized calcium levels were always normal but I had two parathyroid adenomas that had to come out. I read somewhere that hyperparathyroidism is like #3 on the endo list, but nobody seems to include it in their testing unless they are suspecting it to be a problem.
Sorry, I'm getting long winded but it just happens to be one of the few things I know about. If you want to know more about it let me know and if you want to tell me where to find out about the calcium channel autoantibodies I would love to know about them.
(I'm wondering if the extreme sunlight sensitivity and pHPT might be two different problem areas instead of automatically connected because some pHPT people do not have that problem.)