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

Not Applicable

Completed

• Conditions: Vitamin D Deficiency; Prediabetes
• Interventions: Dietary Supplement: Cholecalciferol (vitamin D3)

• 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

Arm && Interventions

Group	Intervention	Description
1	Cholecalciferol (vitamin D3)	Each subject was evaluated and data was collected before and after the intervention

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