Vitamin D for Established Type 2 Diabetes (DDM2) (DDM2)

This study is currently recruiting participants. (see Contacts and Locations)
Verified May 2013 by Tufts Medical Center
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Information provided by (Responsible Party):
Tufts Medical Center Identifier:
First received: November 15, 2012
Last updated: May 24, 2013
Last verified: May 2013
This research study in adults with established type 2 diabetes will test whether daily vitamin D supplementation affects how the body processes glucose (sugar).

Condition Intervention Phase
Type 2 Diabetes
Drug: Cholecalciferol
Drug: Placebo
Phase 2
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Treatment

Resource links provided by NLM:

Further study details as provided by Tufts Medical Center:

Primary Outcome Measures:
  • Disposition index [ Time Frame: 6 months ] [ Designated as safety issue: No ]
    Disposition index by the insulin secretion sensitivity index-2 (ISSI-2)

Secondary Outcome Measures:
  • Change in glycemia [ Time Frame: 6 and 12 months ] [ Designated as safety issue: No ]
    Change in glycemia (categorical variable, composite outcome) defined as [1] a decrease in diabetes medications or [2] a reduction of equal to or more than 0.4 HbA1c units from baseline without increasing medications.

Other Outcome Measures:
  • Hemoglobin A1c [ Time Frame: 6 and 12 months ] [ Designated as safety issue: No ]
  • Change in diabetes medications [ Time Frame: 6 and 12 months ] [ Designated as safety issue: No ]
  • Variability of response to vitamin D supplementation in subgroups. [ Time Frame: 6 and 12 months ] [ Designated as safety issue: No ]
    Variability of response to vitamin D supplementation in subgroups defined by baseline characteristics: (1) race; (3) 25OHD concentration; (3) diabetes treatment.

  • Effect of vitamin D supplementation on blood 25-hydroxyvitaminD concentration [ Time Frame: 6 and 12 months ] [ Designated as safety issue: No ]
  • Cardiovascular risk factors [ Time Frame: 6 and 12 months ] [ Designated as safety issue: No ]
    Cardiovascular risk factors defined as blood pressure, lipid profile, C-reactive protein and urine albumin excretion

Estimated Enrollment: 124
Study Start Date: December 2012
Estimated Primary Completion Date: December 2016 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Placebo Comparator: placebo
One placebo pill daily for 1 year
Drug: Placebo
Active Comparator: cholecalciferol
One cholecalciferol pill daily for 1 year
Drug: Cholecalciferol


Ages Eligible for Study:   25 Years to 75 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Established type 2 diabetes, defined by one of the following two criteria:
  • Age ≥ 25 years and ≤ 75 years
  • BMI: 23 to 40 kg/m2 inclusive
  • Provision of signed and dated written informed consent prior to any study procedures.

Major Exclusion Criteria

  • "Severe" diabetes defined by one of the following criteria:
  • - (a) Symptoms of hyperglycemia;
  • - (b) Screening HbA1c ≥ 7.5 [may indicate potential for rapid progression during the trial necessitating need to amplify diabetes-specific pharmacotherapy]
  • History of nephrolithiasis or hypercalcemia
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01736865

United States, Massachusetts
Tufts Medical Center Recruiting
Boston, Massachusetts, United States, 02111
Contact: Paul Fuss    617-636-2834   
Principal Investigator: Anastassios Pittas, MD MS         
United States, Ohio
Cincinnati VA Medical Center Recruiting
Cincinnati, Ohio, United States
Contact: Colleen Rogge    513-475-6478   
Principal Investigator: David D'Alessio, MD         
Sponsors and Collaborators
Tufts Medical Center
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
  More Information

Responsible Party: Tufts Medical Center Identifier: NCT01736865     History of Changes
Other Study ID Numbers: DK76092-06  R01DK076092 
Study First Received: November 15, 2012
Last Updated: May 24, 2013
Health Authority: United States: Federal Government

Additional relevant MeSH terms:
Diabetes Mellitus, Type 2
Diabetes Mellitus
Endocrine System Diseases
Glucose Metabolism Disorders
Metabolic Diseases
Bone Density Conservation Agents
Growth Substances
Pharmacologic Actions
Physiological Effects of Drugs
Vitamins processed this record on April 27, 2016