First of all, let me just say I'm new and almost everything I read is out of my range.I'm trying to put some things together for myself. This is for the ones that aren't able to be out in the sun. Is it the summer sun? Or any sun? I lost many years with lack of diagnosis for hyperparathyroidism. Most dr's don't/can't diagnosis it, so I finally figured out mine and went on forums for it to learn more. Some members could not bear the sunlight and they said it had to do with the vit. D3. With hyperparathyroidism, vit. D plays a big factor. I don't know if it has anything to do with this post, but I thought I'd throw it out there, FWIW.