[Expert Solution]: An 82-year-old woman living in a nursing…

An 82-year-old woman living in a nursing home feels unsteady on her feet and does not wander outside anymore. She has lactose intolerance and has never been able to drink milk. She does not take any dietary supplements. She says, “I feel my age, doc,” but otherwise has no specific com- plaints. On her annual laboratory assessment, her calcium level is found to be slightly low at 8.2 mg/dL (normal, 8.5 to 10.2 mg/dL) with albumin 3.5 g/dL (normal, 3.5 to 4.8 g/dL), BUN 28 mg/dL, and creatinine 1.1 mg/dL. This prompts further evaluation, which reveals PTH elevated at 181 Pg/mL and 25-hydroxy vitamin D low at 6 ng/mL