Overview

This trial is active, not recruiting.

Conditions vitamin d deficiency, secondary hyperparathyroidism, obesity
Treatments ergocalciferol, cholecalciferol
Phase phase 4
Sponsor Weill Medical College of Cornell University
Start date February 2006
End date July 2007
Trial size 60 participants
Trial identifier NCT00288873, 0509008122

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.

United States No locations recruiting
Other Countries No locations recruiting

Study Design

Allocation randomized
Endpoint classification safety/efficacy study
Intervention model parallel assignment
Masking open label
Primary purpose treatment

Primary Outcomes

Measure
Vitamin D (25OHD):RIA and HPLC
time frame:
Parathyroid hormone (PTH):iPTH and 3rd generation RIA
time frame:

Secondary Outcomes

Measure
Parathyroid hormone carboxy terminal fragment levels PTH(7-84)
time frame:
Ratio of PTH (1-84) to PTH (7-84)
time frame:
Serum calcium level
time frame:
Urine calcium level
time frame:

Eligibility Criteria

Male or female participants from 18 years up to 65 years old.

Inclusion Criteria: - Obese subjects with body mass indices greater than 40 kg/m2 or 35 kg/m2 with other medical conditions secondary to obesity - Willingness to take vitamin D supplements - If baseline vitamin D level is >25 ng/ml subjects will be eligible for the control group - If baseline vitamin D level is <25 ng/ml subjects will be eligible for one of the two vitamin D replacement groups Exclusion Criteria: - Hypercalcemia - Kidney disease - Liver disease - Malabsorption - Prior diagnosis of bone disease - Medical conditions requiring daily use of calcium, antacids, or medications known to affect bone metabolism or interact with vitamin D - Hypersensitivity to any formulation of vitamin D

Additional Information

Official title Characterization of Hyperparathyroidism and Vitamin D Deficiency in Obesity
Principal investigator Emily M Stein, M.D.
Trial information was received from ClinicalTrials.gov and was last updated in July 2007.
Information provided to ClinicalTrials.gov by Weill Medical College of Cornell University.