Vitamin D and Calcium Homeostasis for Prevention of Type 2 Diabetes

Phase 1

Completed

• Conditions: Metabolic Syndrome; Glucose Intolerance; Type 2 Diabetes Mellitus
• Interventions: Drug: Calcium Carbonate 400 mg orally twice daily; Drug: Vitamin D3 2,000 IU orally once daily; Drug: Vitamin D3-Placebo; Drug: Calcium-Placebo

• Registration Number: NCT00436475
• Lead Sponsor: Tufts Medical Center

Brief Summary

The purpose of the randomized trial is to quantify the effect of vitamin D and calcium supplementation on beta-cell function, insulin sensitivity, glucose tolerance and systemic inflammation and other cardiometabolic outcomes in ambulatory adults at high risk for type 2 diabetes.

Detailed Description

There is animal and human observational evidence to suggest that vitamin D and calcium are important in modifying t2DM risk but there are critical gaps in our knowledge about the clinical magnitude of the association with t2DM and potential mechanisms in humans. We are conducting a randomized trial to quantify the effect of vitamin D and calcium supplementation on beta-cell function, insulin sensitivity, glucose tolerance and systemic inflammation and other cardiometabolic outcomes in ambulatory adults at high risk for t2DM. We anticipate that the research proposed in this application is significant because it will provide the basis for defining feasible nutritional interventions that promotes prevention of t2DM. Based on the results of the proposed studies and future work in this area, vitamin D and calcium supplementation can assume an important role in the treatment of t2DM and in the prevention of the disease in the 41 million Americans who are at risk of developing t2DM.

Study Timeline

• Study First Submitted: 2007-02-16
• Study First Submitted QC: 2007-02-16
• Study First Posted: 2007-02-19
• Study Start: 2007-09
• Primary Completion: 2009-11
• Study Completion: 2009-11
• Results First Submitted: 2016-09-26
• Status Verified: 2019-07
• Results First Submitted QC: 2019-07-08
• Last Update Submitted: 2019-07-08
• Results First Posted: 2019-07-30
• Last Update Posted: 2019-07-30

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 92

Inclusion Criteria

• Ethnicity: all ethnic groups

• Gender: men and women

• Age

  1. Lower age limit: 40 years inclusive
  2. Upper age limit: NONE

• BMI

  1. Lower BMI limit: 25 inclusive
  2. Upper BMI limit: 40 inclusive

• Glucose Intolerance / Mild Diabetes defined as

  1. Fasting glucose ≥100 mg/dl OR
  2. 2-hr glucose after OGTT ≥140 mg/dl OR
  3. 5.8 ≤ Hemoglobin A1c ≤ 7

Major

Exclusion Criteria

• Diabetes requiring pharmacotherapy
• Smoking
• Hyperparathyroidism
• Hypercalcemia (Calcium > 10.5 mg/dl)
• Kidney stone
• Pregnancy

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: FACTORIAL

Arm && Interventions

Group	Intervention	Description
3	Calcium Carbonate 400 mg orally twice daily	Vitamin D3-Placebo plus Calcium Carbonate 400 mg twice daily
1	Vitamin D3 2,000 IU orally once daily	Vitamin D3 2,000 IU daily plus Calcium Carbonate 400 mg twice daily
1	Calcium Carbonate 400 mg orally twice daily	Vitamin D3 2,000 IU daily plus Calcium Carbonate 400 mg twice daily
3	Vitamin D3-Placebo	Vitamin D3-Placebo plus Calcium Carbonate 400 mg twice daily
2	Calcium-Placebo	Vitamin D3 2,000 IU daily plus Calcium-Placebo twice daily
2	Vitamin D3 2,000 IU orally once daily	Vitamin D3 2,000 IU daily plus Calcium-Placebo twice daily
4	Vitamin D3-Placebo	Vitamin D3-Placebo plus Calcium-Placebo
4	Calcium-Placebo	Vitamin D3-Placebo plus Calcium-Placebo

Primary Outcome Measures

Name	Time	Method
Chang in Disposition Index, a Measure of Beta Cell Function	baseline and 4 months	Range is 0 to infinity Lower is better.

Secondary Outcome Measures

Name	Time	Method
Change in Hemoglobin A1c	Baseline to 4 months	This outcome measures change in Hemoglobin A1c, a measure of glycemia

Trial Locations

Locations (1)

Tufts-New England Medical Center; 🇺🇸 Boston, Massachusetts, United States