title: Thyroid hormone and parathyroid hormone competing to maintain calcium levels in the presence of vitamin D deficiency.
abstract: Weight loss and bone disease in the elderly are very often attributed to malignancy. Rarely, benign treatable conditions may be overlooked. Thyrotoxicosis, a benign treatable condition, needs to be excluded in such patients. The diagnosis may be delayed, since the symptoms are often subtle, and secondary complications including bone disease (osteoporosis) are therefore more frequent at the time of presentation. The case presented here illustrates this well, and also highlights the value of measuring vitamin D levels in such patients. The most interesting aspect of this case was the reciprocal relationship between thyroxine and parathyroid hormone observed in maintaining calcium homeostasis in this thyrotoxic patient with low vitamin D levels.
authors.affiliation: Department of Nuclear Medicine, Guy's and St. Thomas Hospital NHS Trust, London, United Kingdom. mohanhk@hotmail.com
authors.forename: Hosahalli K
authors.initials: HK
authors.lastname: Mohan
authors.forename: Ashley M
authors.initials: AM
authors.lastname: Groves
authors.forename: Ignac
authors.initials: I
authors.lastname: Fogelman
authors.forename: Susan E M
authors.initials: SE
authors.lastname: Clarke
mesh_terms: D002118:Calcium / Q000097:blood*; D005260:Female; D006706:Homeostasis; D006801:Humans; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000378:metabolism*; D013971:Thyrotoxicosis / Q000097:blood / Q000150:complications*; D013974:Thyroxine / Q000378:metabolism*; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications*
chemical_list: D010281:Parathyroid Hormone; D013974:Thyroxine; D002118:Calcium