Vitamin D and Calcium Homeostasis for Prevention of Type 2 Diabetes (CaDDM)

Tufts University

Status and phase: Completed; Phase 2; Phase 1

Conditions: Type 2 Diabetes Mellitus; Metabolic Syndrome; Glucose Intolerance

Treatments: Drug: Calcium Carbonate 400 mg orally twice daily; Drug: Vitamin D3 2,000 IU orally once daily; Drug: Calcium-Placebo; Drug: Vitamin D3-Placebo

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT00436475

DK76092 (completed)

R01DK076092 (U.S. NIH Grant/Contract)

DK76092

Details and patient eligibility

About

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.

Full 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.

Enrollment: 92 patients

Sex: All

Ages: 40+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion and exclusion criteria

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

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Factorial Assignment

Masking: Quadruple Blind

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92 participants in 4 patient groups

1

Other group

Description:

Vitamin D3 2,000 IU daily plus Calcium Carbonate 400 mg twice daily

Treatment:

Drug: Vitamin D3 2,000 IU orally once daily

Drug: Calcium Carbonate 400 mg orally twice daily

2

Other group

Description:

Vitamin D3 2,000 IU daily plus Calcium-Placebo twice daily

Treatment:

Drug: Vitamin D3 2,000 IU orally once daily

Drug: Calcium-Placebo

3

Other group

Description:

Vitamin D3-Placebo plus Calcium Carbonate 400 mg twice daily

Treatment:

Drug: Vitamin D3-Placebo

Drug: Calcium Carbonate 400 mg orally twice daily

4

Other group

Description:

Vitamin D3-Placebo plus Calcium-Placebo

Treatment:

Drug: Vitamin D3-Placebo

Drug: Calcium-Placebo