Effect of Vitamin D Deficiency and Vitamin D Supplementation on Glucose Metabolism

Not Applicable

Completed

• Conditions: Vitamin D Deficiency; Prediabetes

• Registration Number: NCT00749918
• Lead Sponsor: University of Minnesota

Brief Summary

This study was intended to evaluate the effect of vitamin D supplementation on insulin sensitivity and pancreatic islet beta-cell function. Our hypothesis was that vitamin D supplementation to normal levels in patients with impaired fasting glucose will result in improved insulin sensitivity and improved beta cell function.

Detailed Description

A modified frequently sampled intravenous glucose tolerance (mFSIGT) test was used. On day 0, baseline 22 time point mFSIGT was performed. Subjects were then treated with cholecalciferol (vitamin D3) supplementation - 10,000 IU/day - for 28 consecutive days. mFSIGT was then repeated measuring glucose, insulin and c-peptide at all time points. 25-OH vitamin D, PTH, and calcium were also measured at time point 0 pre and post vitamin D supplementation. Data was analyzed using the Bergman/Boston minimal model for insulin homeostasis with MinMod Millennium software.

Study Timeline

• Study Start: 2007-01
• Primary Completion: 2008-06
• Study Completion: 2008-06
• Study First Submitted: 2008-09-08
• Study First Submitted QC: 2008-09-08
• Study First Posted: 2008-09-09
• Status Verified: 2008-10
• Last Update Submitted: 2008-10-16
• Last Update Posted: 2008-10-20

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 12

Inclusion Criteria

• Impaired fasting glucose
• Adult, age between 18 and 65
• Serum vitamin D level below 30 ng/mL

Exclusion Criteria

• History of nephrolithiasis
• Any medications that can effect insulin sensitivity or beta cell function (i.e. antipsychotics, metformin)
• Pregnancy
• Liver disease
• Renal disease

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Primary Outcome Measures

Name	Time	Method
Assessment of insulin sensitivity before and after oral vitamin D3 supplementation with 10,000 IU/day for one month.	At baseline and after 4 weeks of vitamin D supplementation

Secondary Outcome Measures

Name	Time	Method
Monitor effect of vitamin D supplementation with 10,000 IU/day for one month on serum calcium and parathyroid hormone levels.	One month
Assess effect of vitamin D supplementation on beta cell function as measured by analysis of data collected through a modified FSIGT test.	One month

Trial Locations

Locations (1)

University of Minnesota, Division of Endocrinology; 🇺🇸 Minneapolis, Minnesota, United States