Vitamin D, part 2: Shannon's story
While hypervitaminosis D is a real syndrome, as evidenced by this story, low Vitamin D levels are endemic in temperate and northern latitudes. We did a study several years ago ( Vitamin D Status in an Elective Orthopedic Surgical Population. Foot Ankle Int. 2016 Feb;37(2):186-91. doi: 10.1177/1071100715609054) in Vermont among healthy folks who were going to get surgery and roughly 2/3 had low vitamin D levels (<30ng). Low vitamin D is a significant risk factor for fractures, such as hip fractures in the elderly which is a major cause of mortality. So please don't interpret this story as a reason to avoid any vitamin D supplementation. 1-2000 IU/day has been shown to be safe with long term use, but if you have any questions, you should absolutely talk with your primary care provider.
PS - Yes, I am a practicing physician.