Characterization of Hyperparathyroidism and Vitamin D Deficiency in Obesity
Status:
Completed
Trial end date:
2007-07-01
Target enrollment:
Participant gender:
Summary
Obese persons are known to have elevated levels of parathyroid hormone (PTH) and low levels
of vitamin D. These hormones are important in regulation of the body's calcium stores and
bone health. We would like to investigate these abnormalities and the accuracy of our current
diagnostic tests by comparing results of standard assays for vitamin D and PTH to more
specific tests, in obese subjects at baseline and as vitamin D is replaced. We will also
compare two standard vitamin D replacement regimens to determine if one is more effective.
This is a pilot study with two parts: Part 1 will compare levels of PTH and vitamin D using
two different assays in obese subjects who have normal vitamin D and those who do not. We
plan to enroll 20 subjects who have normal vitamin D levels and 40 subjects who have vitamin
D insufficiency. All subjects will fill out questionnaires about the amount of calcium and
vitamin D in their diet, and their recent sunlight exposure. We will ask for blood samples so
that we can measure levels of calcium, vitamin D, albumin, creatinine, glucose, insulin and
the different forms of PTH.
Subjects who have vitamin D insufficiency will then be randomized to receive Vitamin D2 or
Vitamin D3 in standard doses for eight weeks, in an open label trial. At four and eight
weeks, these subjects will fill out the above questionnaires and have the blood tests
repeated. For safety purposes, urine calcium will also be monitored.
Phase:
Phase 4
Details
Lead Sponsor:
Weill Medical College of Cornell University
Treatments:
Cholecalciferol Ergocalciferols Vitamin D Vitamins